@MaggieDP 

Please ask users to clear caches and check the issue is resolved.

Close all IFS related applications/Windows
1)    Run the below command in command prompt.  rundll32 %windir%\system32\dfshim.dll CleanOnlineAppCache.
2)    Go to following folder and delete/rename C:\Users\<User_name>\AppData\Local\IsolatedStorage
3)    Go to following folder and delete /rename C:\Users\<User_name>\AppData\Local\Apps\2.0 

Here the <Username> = logged in user name.

If this is happening across multiple users, as I suspect it is, the above advice is probably only useful if the users are also experiencing other issues (screens not loading, download packages hanging, etc).  Unfortunately, the only way to start chasing this is with a lot of questions to the users.

How long since the last login?

Network, VPN, or direct access to environment?

How many screens open when it occurs?

Hardware being used (type of laptop, particular software loaded on each system, etc)?

I have experienced this problem from time to time (V9 UD13), clearing the cache and other things mentioned isn’t what I would call the solution.  It may help some individual users, but I don’t see it as the root cause to this issue.

You almost have to have the users log every instance of several questions like this to try to correlate what might be occurring.  It could be something you have on the corporate network running at a certain time (virus scan, backup, malware detection, or any number of things) that is interfering.

I can say I’ve not found anything to mitigate the occurrence other than regularly restarting IFS sessions (every couple of days at longest) and regular reboots of the machine (no longer than weekly).  This has given me the best stability.  This is just personal experience, we don’t have a widespread issue involving multiple users.

Is this still an issue for your team? We have a similar issue and it was identified it is due to the increasing number of handles as IFS was nto clearing them. R&D is working on a patch but they gave us a notification to help the users save their work before it crashes. Another work around was to increase the number of handles in your windows settings.