Troubleshooting multi-user connection problems

This is a check list for a multi-user problems where the connection from the client to multi-user server is not working or is continuously breaking.

1. Check that all users are using same SP version
2. Make sure that the server has static IP address
3. Is the latest multiuser server installed
4. Check that the computers on the same multi-user network have a unique ID number and identical Subnet masks
5. Try using the server’s IPv4 address instead of the server name. For that, check which IPv4 address the server is using (e.g., lets’ assume it’s 10.0.0.11) and then use that address as the multiuser server address in Tekla Structures (e.g., 10.0.0.11 or 10.0.0.11,1238).
6. Try using another server computer as a host for the multiuser server.
7. Ask your IT support to check that the TCP port 1238 is open on the server’s firewall (so the client computers have access to it) and that the Tekla Structures Multiuser Server service is running without errors (e.g., it should run constantly without unexpected restarting).
8. Check duplicates with Active Multi-Users command - multiple process handles with the same username on the multiuser server even though no Tekla Structures sessions are open anymore. The processes might have been left there during some network connection breaks or after software crashing.
9. Check the session history log file for errors:

• error 5 = connection broken (for example a longer network break or firewall cutting the connection in case of long inactivity)
• error 125 = connection badly broken, reconnect needed.

10. Are there any errors in xs_server.log is by default locating in C:\Program data\TeklaStructuresServer\xs_server.log
11. Are there any errors related to the multiuser server logged in Windows System log? Check Windows Event Viewer on the server for that.  

Testing the network connection from client computer to server

With these steps you can try to verify if this is a network problem. Do the following steps on at least one of the client computers where some multi-user error message normally appears (IP address 123.456.7.890 should be replaced with the IP address of your multi-user server):

1. Open Command Prompt.
2. Give command ping 123.456.7.890-t
3. This starts a continuous ping process. (https://www.tunnelsup.com/continuous-ping/)
4. Continue working normally with Tekla Structures.
5. When the error message about Tekla Structures multi-user service appears, go to the command prompt and see if there is anything usual.
6. When the connection is fine, the Command Prompt window fills up with rows like this:

   Reply from 123.456.7.890: bytes=32 time=108ms TTL=56
   Reply from 123.456.7.890: bytes=32 time=108ms TTL=56
   Reply from 123.456.7.890: bytes=32 time=110ms TTL=56
   Reply from 123.456.7.890: bytes=32 time=107ms TTL=56

   Request timed out.
   Request timed out.
   Request timed out.

7. Stop the continuous ping process by pressing Ctrl+c.
8. You get ping statistics:

   Ping statistics for 123.456.7.890:
       Packets: Sent = 172, Received = 171, Lost = 1 (0% loss),
   Approximate round trip times in milli-seconds:
       Minimum = 107ms, Maximum = 219ms, Average = 110ms

If there are plenty of Request timed out messages you can suspect that there is a network issue. This could be caused for example by a broken hardware on the network, such as a router or a switch.
If there is nothing suspicious in the Command Prompt, this is not a network problem. We can continue checking where else the problem might be. It could be for example the port, the multi-user server application, or Tekla Structures.

IT infrastructure troubleshooting

Here are some further troubleshooting advises from our IT specialist:

• Verify that switch ports (both server and client) show no errors, duplex settings are correct and that there are no unknown link up/down events
• Verify that switch has correct STP (spanning tree) settings and ports are configured in correct way for STP
• Check if port authentication and/or re-negotiation causes issues
• Check that both client and server firewall (if present) doesn't cause unwanted interruption.
• Verify how connection from client to server is done (with IP, with DNS name) and check that connections are successfully opened and maintained (netstat)
• Find out any tweaks or changes done compared to default operating system installation, especially regarding network
• Check whether all other applications and services work without any issue.

Offline files

In some cases we have found out that disabling offline files in Windows Sync Center helps with weird multi-user connection problems. You find this setting under the Manage offline files in the Sync Center.

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