"You have reached maximum allowed number of concurrent sessions "

What do you have the this setting configured as in the Admin console?

More information available here.

Idle Session Timeout (Minutes) - 60 mins

Maximum Concurrent Sessions - 3

And this is only affecting a single user?

Is this user signing in via different browsers simultaneously?

Only single user at this time. we had the same complaint from another user couple weeks ago

Is this user signing in via different browsers simultaneously? >> No

Can you check if the user is actually signing off from Appian before login back again? If user does not sign off and just close the window the session will not be killed immediately.

Hi @Ramanan I believe you need to raise a support ticket to Appian Team.

They can help you in resolving this issue.

Perhaps clearing cookies / browser data can help resolve this too.

Another Thought I had:

If your platform is a multiple node instance, then it is possible to log in to one node. Exit your internet browser. Go to your environment, but be routed to a different node. Now you have two concurrent sessions on two nodes, but without editing your cookies (to directly hit the node you want), you can not access the first node to log off. Rinse, repeat, and if you're unlucky, you'll be connected to a third different node.

Best way to mitigate a multiple node logins resulting in max concurrent sessions is to have a low idle timeout session. In this way, any node you are still logged into, will timeout in a reasonable time, allowing a new login. You could also consider having your concurrent sessions = to the number of nodes for you system.

Can you try clearing your browser history and cache an then close the browser and restart. I suppose this may work.