Lightroom Classic: HDR Merged photos crop themselves and/or break up

This looks like a corrupt file. Have you checked your hard drive where this is stored to make sure it isn't failing? That would be good first troubleshooting step. 

I don't believe the file is corrupt, and the drive is healthy. It happens in whatever drive I save it to. If I actually click and view the picture, the "corruptness" goes away. The crops are what I'm more concerned about, as it messes up my batch exporting. 

A few things to try:

• Ensure Video Drivers Are up to Date
• Try it with GPU on and Off
• Reset Preferences

Reset Procedure:

1. Close Lightroom.

2. Hold down [Alt/Opt]+[Shift] while restarting Lightroom.

3. Overwrite the Preferences when prompted by the dialog.

4. Close Lightroom.

5. Restart Lightroom.

Reset Procedure:

1. Close Lightroom.

2. Hold down [Alt/Opt]+[Shift] while restarting Lightroom.

3. Overwrite the Preferences when prompted by the dialog.

4. Close Lightroom.

5. Restart Lightroom.

Is there a way to revert to the previous version of Lightroom? 

Here's how to revert to a previous version:

https://helpx.adobe.com/lightroom-classic/kb/roll-back-to-prior-update.html

Looks like the update is the problem 

Not seeing the issue again after reverting to 9.4 

I am not seeing any other reports nor your issue on my end. I wonder if the uninstall/reinstall cleared something from a bad previous install. 

I reinstalled 10. I'll let you know if it happens again

@Rikk, wanted to comment that I've been running into this problem with regularity for some weeks now. Using LR Classic 10.1 with a 2020 iMac on OS 10.15.7. Doesn't matter whether my GPU is on or off. What is frustrating is that if I delete the corrupt HDR and rerun from the originals, it STILL comes in corrupted. Also, if I move the originals to my 2013 MacBook Air (LR 10.1, OS 10.15.7) and run the HDR it works..but when I move that HDR over to my iMac it immediately corrupts! Update: looks like resetting the preferences as Rikk laid out above did solve it (at least on this image).

Have you attempted a clean reinstall?

Clean Lightroom Install Procedure

Close Lightroom

Restart the computer

Use the Adobe Creative Cloud App to uninstall Lightroom

Restart the computer

Install Lightroom via the Creative Cloud App without launching any other programs.

Restart the computer

Launch Lightroom

Wait 5 minutes