This might be more of an optimization thing, as it's not actually a bug.

This happened to me the other night while making some session preparations, while working with the Assets, I accidentally pressed enter after only typing in one letter to search for.
The Asset search started and kept going for over five minutes, at which point I used the Task Manager to shut down FGU, as it was frozen and unresponsive during this process.

This was an inconvenience during campaign prepping, but during a live game this would be rather worse.

I think I may have mentioned something to the effect before a while back, to give us some way to cancel, break or exit out of the procedures that are taking to long in the program.