I have a T2 with the firmware upgrade.
I have the same problem with 9250 files and 24 pages of Collections. So far, nothing really happens other than I give it a few minutes before 'Force Closing', then going about my business. Doesn't happen all the time, just once in a while.
I think that something is timing out while waiting for indexing, but catches up if you give it a minute or so.
It's annoying, but hasn't seemed to affect anything. (So Far)