This article lists the error codes you may receive when connecting via dial-up or VPN.
Applies to:Windows 10 - All Editions, Windows Server 2012 R2
Original KB Number:824864
The following list contains error codes for dial-up or VPN connections:
600
An operation is pending.
601
The port handle is invalid.
602
The door is already open.
603
The caller's buffer is too small.
604
Incorrect information was identified.
605
Unable to set port information.
606
The port is not connected.
607
The event is not valid.
608
The device does not exist.
609
The device type does not exist.
610
The buffer is invalid.
611
The route is not available.
612
Path not assigned.
613
Invalid compression specified.
614
Out of two buffers.
615
Port not found.
616
An asynchronous request is pending.
617
The port or device is already disconnected.
618
The door is not open.
619
The port is disconnected.
620
There are no endpoints.
621
Unable to open phonebook file.
622
Unable to load phone book file.
623
Unable to locate phone book entry.
624
Unable to write phonebook file.
625
Invalid information found in phone book.
626
Unable to load a string.
627
The key could not be found.
628
The port is disconnected.
629
The port was disconnected from the remote machine.
630
The port has been disconnected due to hardware failure.
631
The port was disconnected by the user.
632
The frame size is wrong.
633
The port is already in use or is not configured for remote dial-up access.
634
Unable to register your computer on the remote network.
635
Unknown error.
636
The wrong device is connected to the port.
637
Could not convert string.
638
The request has expired.
639
No asynchronous network available.
640
A NetBIOS error occurred.
641
The server cannot allocate the necessary NetBIOS resources to support the client.
642
One of your NetBIOS names is already registered on the remote network.
643
A network adapter on the server has failed.
644
You will not receive network pop-up messages.
645
Internal authentication error.
646
The account is not allowed to log in at this time of day.
647
Account is disabled.
648
Password has expired.
649
The account does not have remote access permission.
650
The remote access server is not responding.
651
Your modem (or other connecting device) reported an error.
652
Unrecognized device response.
653
A macro required by the device was not found in the device's .INF file section.
654
A command or response in the device's .INF file section references an undefined macro
655
A macro
656
A macro
657
Could not open device .INF file.
658
The device name in the device's .INF file or .INI media is too long.
659
The media .INI file refers to an unknown device name.
660
The device's .INF file contains no responses to the command.
661
A command is missing from the device's .INF file.
662
Attempting to define a macro that is not listed in the device's .INF file section.
663
The media .INI file refers to an unknown device type.
664
Unable to allocate memory.
665
The port is not configured for remote access.
666
Your modem (or other connecting device) is not working.
667
Unable to read media .INI file.
668
Connection dropped.
669
The usage parameter in the media .INI file is invalid.
670
Unable to read module name from media .INI file.
671
Unable to read device type from media .INI file.
672
Unable to read device name from media .INI file.
673
Unable to read media .INI file usage.
674
Unable to read maximum connection BPS rate from media .INI file.
675
Unable to read the maximum BPS rate of the carrier from the media .INI file.
676
The line is busy.
677
A person answered instead of modem.
678
There is no answer.
679
Unable to locate carrier.
680
There is no dial tone.
681
General error reported by the device.
682
ERROR TYPING SECTIONNAME
683
ERROR WRITING DEVICE TYPE
684
ERROR SPELLING THE DEVICE NAME
685
MAXCONNECTBPS WRITE ERROR
686
ΣΦΑΛΜΑ ΓΡΑΦΗΣ MAXCARRIERBPS
687
USING REGISTRATION ERROR
688
DEFAULTOFF REGISTRATION ERROR
689
DEFAULT READ ERROR
690
INI FILE EMPTY ERROR
691
Access is denied because the username and/or password are not valid for the domain.
692
Hardware error on connected port or device.
693
NON-BINARY LONG ERROR
694
DCB ERROR NOT FOUND
695
ERROR STATUS MACHINES FAILED TO START
696
STATE MACHINE ERROR ALREADY STARTED
697
PARTIAL ERROR RESPONSE LOOP
698
A response key name in the device's .INF file is not in the expected format.
699
The device response caused a buffer overflow.
700
The extended command in the device's .INF file is too long.
701
The device was switched to a BPS rate not supported by the COM driver.
702
Received a device response when none was expected.
703
INTERACTIVE MODE ERROR
704
ERROR WRONG REPEAT NUMBER
705
ERROR INVALID AUTHORIZATION STATUS
706
INITBPS WRITE ERROR
707
X.25 diagnostic indication.
708
The account has expired.
709
Error changing domain password.
710
Serial overflow errors were encountered when communicating with your modem.
711
RasMan initialization failed. Check the event log.
712
The biplex port is being prepared. Wait a few seconds and call again.
713
There are no active ISDN lines available.
714
There are not enough ISDN channels available to make the call.
715
Many errors occurred due to poor phone line quality.
716
Unable to use remote access IP configuration.
717
There are no available IP addresses in the static pool of remote access IP addresses.
718
PPP timeout.
719
PPP terminated by a remote machine.
720
No PPP control protocol configured.
721
The remote PPP peer is not responding.
722
The PPP packet is invalid.
723
The phone number, including the prefix and suffix, is too long.
724
The IPX protocol cannot make a call to the port because the computer is an IPX router.
725
The IPX protocol cannot make a call on the port because the IPX router is not installed.
726
The IPX protocol cannot be used to call more than one port at a time.
727
Unable to access TCPCFG.DLL.
728
Unable to find IP adapter connected to remote access.
729
SLIP cannot be used unless the IP protocol is installed.
730
The computer registry is not complete.
731
The protocol is not configured.
732
PPP negotiation does not converge.
733
The PPP control protocol for this network protocol is not available on the server.
734
PPP link control protocol timed out.
735
The requested address was rejected by the server.
736
The remote computer has terminated the control protocol.
737
Reset detected.
738
The server has not assigned an address.
739
The remote server cannot use the encrypted Windows NT password.
740
TAPI devices configured for remote access failed to initialize or were not installed correctly.
741
The local computer does not support encryption.
742
The remote server does not support encryption.
743
The remote server requires encryption.
744
Cannot use the IPX network number assigned by the remote server. Check the event log.
745
ERROR_INVALID_SMM
746
ERROR_SMM_UNINITIALIZED
747
ERROR_NO_MAC_FOR_PORT
748
ERROR_SMM_TIMEOUT
749
ERROR_BAD_PHONE_NUMBER
750
ERROR_WRONG_MODULE
751
The callback number contains an invalid character. Only the following 18 characters are allowed: 0 to 9, T, P, W, (,), -, @ and space
752
A syntax error occurred while processing a script.
753
The connection could not be disconnected because it was created by the multiprotocol router.
754
The system did not find the multilink package.
755
The system cannot auto dial because this connection has a custom dialer defined.
756
This connection is already being called.
757
Remote Access Services could not be started automatically. Additional information is provided in the event log.
758
Internet connection sharing is already enabled on the connection.
759
An error occurred while changing the existing Internet Connection Sharing settings.
760
An error occurred while enabling routing features.
761
An error occurred while enabling Internet Connection Sharing for the connection.
762
An error occurred while configuring the local network for sharing.
763
Unable to enable internet connection sharing. There is more than one LAN connection other than the connection to be shared.
764
No smart card reader installed.
765
Unable to enable internet connection sharing. A LAN connection is already configured with the necessary IP address for automatic IP addressing.
766
Could not find certificate. Connections using L2TP over IPSec require the installation of a machine certificate, also known as a computer certificate.
767
Unable to enable internet connection sharing. The LAN connection selected as a private network has more than one IP address configured. Please reconfigure your LAN connection with a single IP address before enabling Internet Connection Sharing.
768
The connection attempt failed due to a failure to encrypt the data.
769
The specified destination is not reachable.
770
The remote computer rejected the connection attempt.
771
The connection attempt failed because the network is busy.
772
The remote computer's network hardware is incompatible with the requested call type.
773
The connection attempt failed because the destination number has changed.
774
The connection attempt failed due to a temporary failure. Try logging in again.
775
The call was blocked by the remote computer.
776
The call could not be connected because the remote computer has activated Do Not Disturb.
777
The connection attempt failed because the modem (or other connection device on the remote computer) is faulty.
778
Unable to verify server identity.
779
To call using this connection, you must use a smart card.
780
An operation attempt is not valid for this connection.
781
The connection requires a certificate and no valid certificate was found. For further assistance, click More information or search the Help and Support Center for this error number.
782
Internet Connection Sharing (ICS) and Internet Connection Firewall (ICF) cannot be enabled because routing and remote access are enabled on this computer. To enable ICS or ICF, first disable routing and remote access For more information about routing and remote access, ICS , or ICF, see Help and Support.
783
Unable to enable internet connection sharing. The LAN connection selected as a private network does not exist or is disconnected from the network. Make sure the LAN adapter is connected before enabling Internet Connection Sharing.
784
You cannot make a call using this connection at the time of connection because it is set to use a different username than the one on the smart card. If you want to use it at login time, you need to set it to use the smart card username.
785
You cannot make a call using this connection at the time of connection because it is not configured to use a smart card. If you want to use it at the time of connection, you need to edit the properties of this connection so that it uses a smart card.
786
The L2TP connection attempt failed because there is no valid machine certificate on your computer for security authentication.
787
The L2TP connection attempt failed because the security layer could not authenticate the remote computer.
788
The L2TP connection attempt failed because the security layer could not negotiate compatible parameters with the remote computer.
789
The L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with the remote computer.
790
The L2TP connection attempt failed because the certificate validation on the remote computer failed.
791
The L2TP connection attempt failed because the security policy for the connection was not found.
792
The L2TP connection attempt failed because the security negotiation timed out.
793
The L2TP connection attempt failed because an error occurred during security negotiation.
794
The Framed Protocol RADIUS attribute for this user is not PPP.
795
The Tunnel Type RADIUS attribute for this user is incorrect.
796
The Type of Service RADIUS attribute for this user is neither Framed nor Callback Framed.
797
A connection could not be established to the remote computer because the modem was not found or was busy. For further assistance, click More information or search the Help and Support Center for this error number.
798
Could not find a certificate that can be used with this extensible authentication protocol.
799
Internet Connection Sharing (ICS cannot be enabled due to IP address conflict on the network. ICS requires the host to be configured to use 192.168.0.1. Ensure that no other clients on the network are configured to use 192.168.0.1 .
800
Unable to establish VPN connection. The VPN server may be unreachable or the security parameters may not be configured correctly for this connection.
801
This connection is configured to authenticate the access server, but Windows cannot verify the digital certificate sent by the server.
802
The card provided was not recognized. Make sure the card is inserted correctly and fits snugly.
803
The PEAP setting stored in the session cookie does not match the current session setting.
804
The PEAP identity stored in the session cookie does not match the current identity.
805
You cannot make a call using this connection at the time of connection because it is set to use the credentials of the connected user.
900
The router is not working.
901
The interface is already connected.
902
The specified protocol identifier is not known by the router.
903
Call request interface management is not running.
904
An interface with this name is already registered on the router.
905
An interface with this name is not registered with the router.
906
The interface is not connected.
907
The specified protocol stops.
908
The interface is linked and therefore cannot be deleted.
909
Interface credentials are not set.
910
This interface is already in the process of connecting.
911
An update to the routing information on this interface is already in progress.
912
The interface configuration is invalid. There is already another interface connected to the same interface on the remote router.
913
A remote access client attempted to connect to a port reserved for routers only.
914
A Dial-on-Demand router attempted to connect through a port reserved only for Remote Access clients.
915
The client interface with this name already exists and is currently connected.
916
The interface is in disabled state.
917
The authentication protocol was rejected to the end.
918
There are no authentication protocols available to use.
919
The remote computer refused authentication using the configured authentication protocol. The line has been disconnected.
920
The remote account does not have remote access permission.
921
The remote account has expired.
922
The remote account is disabled.
923
The remote account is not allowed to connect at this time of day.
924
Access to the remote peer is denied because the username and/or password are not valid in the domain.
925
There are no routable ports available for use by this demand call interface.
926
The port has been disconnected due to inactivity.
927
The interface is currently not accessible.
928
Demand Dial service is paused.
929
The interface was disconnected by the administrator.
930
The authentication server did not respond to authentication requests in time.
931
The maximum number of ports allowed for use in the multilink connection has been reached.
932
The login timeout for the user has been reached.
933
The maximum limit on the number of supported LAN interfaces has been reached.
934
The maximum limit for the number of supported call request interfaces has been reached.
935
The maximum limit for the number of supported remote access clients has been reached.
936
Port disconnected due to BAP policy.
937
If another connection of its type is in use, the incoming connection cannot accept your connection request.
938
No RADIUS server found on the network.
939
An invalid response was received from the RADIUS authentication server. Ensure that the case-sensitive secret password for the RADIUS server is set correctly.
940
You are not allowed to log in at this time.
941
You are not allowed to sign in using the current device type.
942
You are not allowed to log in using the selected authentication protocol.
943
A BAP is required for this user.
944
The interface is not allowed to connect at this time.
945
The router's saved configuration is not compatible with the current router.
946
RemoteAccess has detected legacy user accounts that will not be automatically migrated. To migrate them manually, run XXXX.
948
Transport is already installed with the router.
949
Invalid packet signature length received from RADIUS server.
950
Invalid packet signature received from RADIUS server.
951
Did not receive signature along with EAPM message from RADIUS server.
952
Received packet with invalid length or identifier from RADIUS server.
953
Received packet with invalid attribute length from RADIUS server.
954
Invalid packet received from RADIUS server.
955
The authentication does not match the packet from the RADIUS server.
FAQs
What are the error codes for VPN Windows 10? ›
Some most common Windows VPN error codes include 691, 720, 721, 789, 800, 809, 609, 633, 0x80072746, 13801, and 0x800704C9. Each error can indicate a specific problem and have a corresponding solution.
Why is my Windows VPN client not connecting? ›What Causes VPN Not Connecting on Windows 10. VPN connection error can be caused by various reasons, e.g. an overloaded VPN server, outdated VPN software, using the wrong protocol, etc. You can eliminate the causes one by one to fix Windows 10 VPN not connecting problem.
What is error 87 on Windows VPN client? ›VPN Error 87: The parameter is incorrect
This error shows up when there is a problem with the Windows networking stack as a whole.
Error code: 809
The network connection between your computer and the VPN server could not be established because the remote server is not responding. This could be because one of the network devices (e.g., firewalls, NAT, routers) between your computer and the remote server is not configured to allow VPN connections.
- Check your internet connection. ...
- Check your credentials. ...
- Check your VPN server status. ...
- Check your VPN protocol and ports. ...
- Look for VPN software issues. ...
- Check the firewall blocking. ...
- Restart your VPN app. ...
- Reinstall the latest version of your VPN app.
Error code: 13806
IKE failed to find a valid machine certificate. Contact your network security administrator about installing a valid certificate in the appropriate certificate store. Possible cause. This error typically occurs when no machine certificate or root machine certificate is present on the VPN server.
To fix VPN connection problems, you can try restarting your VPN client, resetting your network settings, changing the VPN server location, checking for updates, and contacting your VPN provider's support team for assistance. If the issue persists, you may need to troubleshoot your network configuration or hardware.
How to configure Windows VPN client? ›- Select Start > Settings > Network & internet > VPN > Add VPN.
- Under Add a VPN connection, do the following: For VPN provider, choose Windows (built-in). In the Connection name box, enter a name you'll recognize (for example, My Personal VPN). ...
- Select Save.
- Click the Windows Start button and select the Settings cog.
- Under Windows Settings, select Network & Internet.
- Select VPN from the left menu, then at the right, click Add a VPN connection.
- In the dialog box that opens:
- Set VPN provider to "Windows (built-in)".
- Set Connection name to "UWSP VPN".
Error 720 : ERROR_PPP_NO_PROTOCOLS_CONFIGURED typically occurs if the WAN Miniport (IP) adapter is not bound correctly on your PC. This is true even though the WAN Miniport (IP) adapter might look healthy when you examine the Network adapters node in Device Manager.
What is error 633 in Windows VPN? ›
This issue may occur if the TCP port that is used by the VPN connection is already being used by another program. The VPN connection uses TCP port 1723 to establish a connection. If another program is already using this port, you cannot establish a VPN connection.
What is error code 800 VPN? ›Error 800 occurs when you are trying to establish a new connection to a VPN server. It indicates that messages being sent by the VPN client (you) are failing to reach the server. Many possible reasons for these connection failures exist including: The client device lost the connection to its local network.
What is error 645 on Windows VPN? ›VPN Error Code 645
The error occurs when the VPN server denies a connection because you entered an incorrect username and password.
The explanation of error 778 is “It was not possible to verify the identity of the server“.
What is VPN connection error 1329? ›Why am I receiving error 1329: "You are not allowed to sign in, please contact network administrator"? You may receive this message after successful authentication to the Campus VPN Service if you do not have a valid affiliation in the UCSB Campus Directory.
What are common VPN connection issues? ›Common VPN issues include your VPN not connecting, your IP address still being visible despite the VPN saying it's connected, and your VPN continuously disconnecting. It's usually possible to overcome these issues by resetting your internet, restarting your VPN software, or changing your VPN server/protocol.
Why does my VPN keep disconnecting and reconnecting? ›If your VPN keeps disconnecting and reconnecting, it's likely that data packets are being lost or blocked between your device and the VPN server. This could be due to issues with the VPN client, your router, or your network connection.
How to check if VPN is working? ›There are several different ways to check that your VPN service is working properly and protecting your internet traffic and personal data. Check your IP address. Take note of your current IP address, connect to a VPN server, and recheck the IP address. If it differs from the one you initially noted, your VPN works.
What is error code x80070032? ›If you meet the error 0x80070032 when your phone's user account isn't synced properly with the servers, then you need to switch to the local account. Here is the tutorial: Step 1: Open Settings and then click Accounts. Step 2: Go to the Your info tab and then click Sign in with a local account instead.
What is error code 13868? ›Error code 13868 translates to ERROR_IPSEC_IKE_POLICY_MATCH. Essentially this error indicates that the IKEv2 security policy on the client did not match the configuration on the server.
What is error code 8019001? ›
Generally speaking, the root cause of 0x8019001 is temporary file data or corrupted dependency, so you need to repair the entire suite. Note: Tip: There is always an error code 0x80131500 appearing in Windows Store.
Does firewall block VPN? ›It is possible for a firewall to block certain ports, specifically ones that VPNs use. If your data travels through one of the blocked ports, the firewall will not allow it to pass through, preventing you from communicating using your VPN.
How does VPN client connect to server? ›The client takes the server's public key and uses it to make your data unreadable to ISPs, hackers, and other malicious actors. The data travels to the server, which uses its own private key to make that data usable. The server sends the decrypted data to the website or service you wanted to reach.
How do I allow VPN through my firewall? ›- Go to Control Panel.
- Open System and Security.
- Open Windows Defender Firewall.
- Now, click on Allow an app or feature through Windows Defender Firewall.
- Now click on Change Settings.
- Find your VPN in the list of programs and apps shown.
The VPN type to be provisioned on the device. Specify the name which needs to be displayed as the VPN name on the end user's mobile device. Host name or IP address of the VPN server. Select whether the user must authenticate using password or certificate while initiating the VPN connection.
How to make VPN connection available to all users Windows 10? ›Create a new connection, choose Use my Internet Connect (VPN), then add in the details (i.e. VPN server IP address or host name, and a name for the connection). Make sure you tick the option, Allow other people to use this connection.
How to setup client to site VPN? ›- Prerequisites.
- Step 1: Generate server and client certificates and keys.
- Step 2: Create a Client VPN endpoint.
- Step 3: Associate a target network.
- Step 4: Add an authorization rule for the VPC.
- Step 5: Provide access to the internet.
- Step 6: Verify security group requirements.
But if an app doesn't suit you, Windows 10 has built-in VPN support that can be manually configured. The OS doesn't support OpenVPN however, so we recommend choosing from L2TP/IPSec, SSTP, or IKEv2.
What is the server address for VPN? ›What is a Server name or address of VPN? The VPN server hostaname or in oder words VPN address is the specific location of the VPN server. The address can be an IP address or a domain name.
How to setup L2TP VPN client on Windows 10? ›- In the Windows notification area (System Tray), click the Network icon. A list of available networks and VPNs appears.
- Click the VPN connection. The Network & Internet VPN settings appear.
- Select the VPN connection. Click Connect. ...
- Type your user name and password.
- Click OK.
What are VPN errors? ›
Quick fix. The error message “Unable to establish connection” with error code 800 is a common VPN error. It occurs when the VPN client is unable to reach the server. This error is often caused by a problem with the network connection, for example when the network is down or overloaded.
What is error 720 VPN Windows 10? ›Error 720 : ERROR_PPP_NO_PROTOCOLS_CONFIGURED typically occurs if the WAN Miniport (IP) adapter is not bound correctly on your PC. This is true even though the WAN Miniport (IP) adapter might look healthy when you examine the Network adapters node in Device Manager.
What is error 629 in Windows 10 VPN? ›Error 629 generally means that the remote computer (ISP) is closing / disconnecting the port.
What is the error code for connection failure? ›Error 651 indicates that an attempt at a connection to the internet was unsuccessful, or an existing connection has been terminated.
What is error 618 on dial-up? ›This means that the port of the dial up modem is not open or there are some hardware failure. Make sure that there are no other devices that is sharing with the same phone line on the computer then restart the machine.
What is error 691 on VPN connection? ›error 691 "The remote connection was denied because the user name and password combination you provided is not recognized, or the selected authentication protocol is not permitted on the remote access server. Additionally, the domain user's bad password count can increment, resulting in an account lockout.
What is error 633 VPN Windows 10? ›This issue may occur if the TCP port that is used by the VPN connection is already being used by another program. The VPN connection uses TCP port 1723 to establish a connection. If another program is already using this port, you cannot establish a VPN connection.
What is Windows VPN error 806? ›In short, the VPN error 806 occurs when the connection between our computer and the VPN server has been established but the VPN remains incomplete.
What is error code 789 on Windows VPN? ›789 is classically bad PSK, but it can also pop up when you've got a bad credential OR when Windows has changed the password protocol on you. If Windows 10, check out the scripts in my signature. Regardless of version, set Encryption to "optional": Windows doesn't support PAP with 'required' encryption.
What is error code 806 in Windows VPN? ›What Exactly is VPN Error 806? The VPN error 806 occurs when even though a connection has been established between your VPN VPN servers and your computer, still the VPN connection is incomplete as a result of which you aren't able to use the VPN.
What is Windows VPN error 619? ›
Causes of VPN error 619
Error 619 mainly happens when we try to connect to a VPN on Windows Machine. This error pops up when an active VPN suddenly gets disconnected from the VPN server or when the computer is attempting to establish a new connection to the VPN server.
As per my research, error: 813 will occur if, you have attempted to establish a second broadband connection while a previous broadband connection is already established using the same device or port.
What is 422 VPN error? ›Reason 422: Lost contact with the security gateway. Troubleshooting: Check your network connection. The machine's IP address changed or the machine is no longer connected to the Internet. Note: The VPN Client is required to disconnect the VPN tunnel for security reasons, if the machines IP Address has changed.