LRC stopping dead

[Newmarket2]

I'm trying to recover from a pc disaster and have reconnected by catalog to the source image files.

But now, I'm finding that in many cases, there are no previews in my library.

I've verified that the source image files are good, but even when I:
LIBRARY>previews>build standard previews

LRC now and then freezes up

To perplex me further, in Task manager, I'm not seeing a LRC process!  and yet, it's open and I'm using it.

What's up with all this?

[AxelMatt]

The first thing that you should try is to switch off the GPU support from the Lightroom preferences and check if that helps to fix the issue.

Go to Lightroom > Preferences > Performance tab > Uncheck "Use Graphics Processor" > Restart Lightroom.

https://helpx.adobe.com/lightroom-classic/kb/lightroom-gpu-faq.html#troubleshooting

https://helpx.adobe.com/lightroom-classic/kb/troubleshoot-gpu.html

If Lightroom doesn't start correctly the please see "Solution 2" in the document behind the second link.

Troubleshoot GPU issues | Lightroom Classic (adobe.com)

Another step is to try to reset the Lightroom preferences.

https://www.lightroomqueen.com/how-do-i-reset-lightrooms-preferences/

It's recommended to backup your preferences before you reset the preferences to the default settings:

https://helpx.adobe.com/lightroom-classic/kb/preference-file-and-other-file-locations.html

If this doesn't help we need more informations about your environment.

Which operating system do you use?

Which version of Lightroom do you use?

Please post the exact version and not only phrases as "recent", "latest" and so on.

Do you get an error message? If yes, please post the exact message or an screenshot. 

[Newmarket2]

Turns out that when I was recovering my original image files, some target folders were empty.  

What's odd is that LR normally tells you when it can't find images in it's library, but I didn't see that this time.

I'm where I need to be now (I think.....).  Thanks for the help!