AB Tutor v9: offline clients

There can be a number of reasons a client is no longer showing as online inside the Console.

The automatic certificate signing rules was set up incorrectly:

Device expiry means that if the Device hasn't contacted the Server within the specified time then it's automatically deleted. This feature is intended for environments where a VM instance is created upon logging in and deleted once the logout occurs. Misuse of this feature can cause security concerns and devices being deleted from the system, causing them to appear as offline.

Duplicate Devices:

If a device was reimaged and the Client was reinstalled and reaccepted as a new device then the old device will linger. If they're not re-added to the group then this can make this appear as offline as the Teachers are looking at the wrong device. Use the device merge tool inside the web UI to resolve this issue. The page for accepting new incoming devices should be checked first.

Duplicate programData directories.

Ask how the customer installed the client(s). If it's through cloning the machine then see the top answer from here:

https://desk.abtutor.com/#knowledge_base/1/locale/en-gb/answer/49/search-return

Networking Issues

This requires the customer sending over the client logs in order to verify that the client is failing to connect to the Central Server. Please make sure they're on version 9.3.14 or higher and check for errors regarding connecting to the Server. This can be stuff like the Central Server's certificate is no longer trusted, the Server address randomly got reset to abcs and they're using a different server address or some proxy in the way. Smoothwall or some such.

Networking Issues Cont.

If the Server address is correct while the logs are showing a host not found it's possible that the Client's own network cache is now incorrect and needs to be cleared. This can be done by restarting the AB Client Service. It's worth checking if these are BYODs as host not found would be expected if the Device is taken home outside of the network where the AB Server is located.

Updated on: 12/05/2026