P: Cannot merge panorama after updating to 10.14.6

If you hire a REAL Mac tech he/she can downgrade you, but it’s many hours. Do a web search in your area.

That's my problem, too. Reinstalling Lightroom is no solution, a clean and fresh install of 10.14.6 is no solution... Adobe's customer service seems to know the problem but decided that this is an Apple-problem because something changed in MacOS regarding memory caching.
Can't work any more with lightroom. Apple does not allow downgrades, no matter what. My system is right now completly useless.
Wondering what happens when 10.15.0 will show same caching behaviour... Lightroom will not be useable then, too.
Exporting RAWs is also impossible, LR freezes. Sorry, but this is really a desaster!
LR needs an update!

Awesome, thanks for reporting the solution.

I uninstalled Lightroom and re-installed it and that has mostly solved the problem.

No luck. Same issues. Adobe, please address the obvious issue.

Yep, but Lightroom can do that itself.

Onyx will do that!

If changing the file name works, then it may indeed be a cache problem. You could start by purging the Camera Raw cache (in the Preferences).

It may be a corrupt cache or application state, or directory damage. Or it might be Lightroom, but you need to rule out that it’s a MacOS issue with your system first.

Please give your Mac the "once over"! Run the free Onyx (https://www.titanium-software.fr/en/o...), reboot. (In Onyx just run almost everything in the Maintenance tab, deselecting things you may not want deleted, like Launch Services . Hit the "Options" button and deselect more stuff like Cookies & Other Site Data, Browser History, Form Values, etc.), then hit Run Tasks. After it's done it will ask for a reboot.

If that doesn’t fix it run Disk Warrior if you can ($120), (https://www.alsoft.com), reboot. If you can’t do Disk Warrior, at least run First Aid from Disk Utility. Also just doing a "Safe Boot" can clear out caches (restart, hold down shift until you see "Safe Boot" on the screen, then reboot normally.

If that doesn’t work try launching Lightroom from your other (admin or test) account, with a new catalog, as a test. Does it run OK? If it does it may be a corrupted preference in your Username/Library folder. Check The Lightroom Queen site for instructions on how to reset your preferences (https://www.lightroomqueen.com).

Good morning Ray,

I have had the same problem and I stumbled on a change (I hesitate to call it a solution) that got things going again: I changed the name of the files. I know. It is completely ridiculous to think that that pano s/w sulks until it sees the file names changed, but it has worked for me more than once. All I can say is try it and if it works we'll ask Adobe how is it that these two things could possibly be related.
Cheers,
Koro