I had just opened a Library window (floating) and prioritised a commentary (High-Definition on Philippians)
I then closed the Library window and L4 crashed
Logs attached
0285.Logos4.log
6560.Logos4Crash.txt
This is with 4.3 B4.
It is repeatable - I have just managed to do it again by moving the commentary in the priorisation panel.
It isn't tied to the resource, it seems to happen if I make any change to the prioritisation settings in the Library
Graham