Version 12 doesn't open

I had a prompt come up when I last was able to open the app.  The prompt was to upgrade the version 12 catalog. I wish I could recall exactly what it said.  But I chose to upgrade the catalog to the newer version with the upgrades. 

By @Benny5FA9

This is normal behavior.

...After doing so, I was unable to open the app.  

 

I hope this helps a little.

By @Benny5FA9

Not really.

Do you get an error message? If yes  please post the full text of any error message(s).

Which operating system do you use?

Which computer hardware, such as CPU; GPU; the amount of RAM; etc do you use?

Is you system up-to-date? Do you have installed all patches and updates for your operating system and all hardware and chipset drivers, especially the graphic driver.

In a first step please try 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