Stuff happens. Is it Lightroom or your system?
* The vast majority of other users aren't having the same problem with the same software, so it's your system.
* You didn't have any problem with last version, and haven't changed anything, so it's the new version of Lightroom software.
You see the fallacy of over-simplification right?
Bottom line: if new version no go:
* fall back to previous version (and hope for better luck with next version), or
* Make changes to your system/data so it runs OK, like it does on (almost) everybody else's system (I know: easier said than done..).
Cheers,
Rob