Hi  @paul 

In normal case this error occurs when the controller do not have write permission to the hard drive/disk.

Check if there is any anti-virus or firewall.

Have you tried to reboot this PC?

paul wrote

Upgraded Omada from 5.9 to 5.14 and today I am getting these:

An unexpected error occurred in MongoDb.  Omada Controller will try to restart it.

 

But it never does...

 

I have removed all java and installed 64 bit.  No change.