Apparently I musn't call this a 'crash', according to Chris Cox. It is a 'Not Responding' state. But the end result to me is probably the same - it stops working and I have to use Task Manager to end it.
Back to 5.7.1, at least it is very stable on my machine. I don't know what damage is caused to the catalog when LR6 goes into the Not Responding state, so I can't trust LR6, and the backup process does not work properly. Is it supposed to be making normal and compressed backups now in LR6?
Well, answering this myself again, I see from Victoria's blog that LR6 is supposed to be making compressed backups now. When I suggested this years ago, the LR team's answer was that this was too flaky!! They were obviously correct!!!!!
Ever since then, I've been compressing the LR backups myself, without any problems.
Does this happen to you?
For me LR6 enters non responsive state anytime I enter Catalog Settings. It doesn't matter if I actually change a setting. Just the mere fact I entered "Catalog Settings" during a work session guarantees a freeze, especially upon exiting the program. Your "issue" with your catalog freezing may have noting at all to do with making compressed back-ups etc...it may lay much sooner in the food chain.
As soon as you enter Catalog Settings it seems I'm doomed from that point on. Maybe you too?
Hope this helps you narrow down the cause.