Lightroom Classic does not open

Update

A specific CACHE file may be at fault:

Mac: /Users/<username>/Library/Caches/Adobe/Lightroom/metrics.json

Win: C:\Users\<username>\AppData\Local\Adobe\Lightroom\Caches\metrics.json 

see : https://www.lightroomqueen.com/community/threads/lrc-cache-causing-crash-metrics-json-but-why.47409/

Having similar issues, I have tried all the fixes mentioned.  Support has had access to my system 3 seperate times and spent 2+ hours each time.  Moving to a different account worked for a few days, it was painful as I had to rebuild parts of my catalog and now I am back to same issue and will not open.  Adobe needs to start commenting on this issue.

Have you tried logging into your Windows computer using a different user account, typically the Admin account, and seeing if LrC will open? If this diagnostic test works, the a problem in the user account you normally use may be the issue.

Is so, see:

Troubleshoot unexpected behavior in specific user account | Adobe

• For MACOS users the MAS solution #3 has been helpful
• For Windows, # 4 has been helpful
• One other Windows member had a registry issue, perhaps #6
• but that is not absolute, so the other solutions may or may not be what is happening.

and, perhaps:

Basic troubleshooting steps to fix issues in Lightroom Classic | Adobe

Have you already tried resetting Lightroom preferences?

This link has some information that may be useful on how to proceed. Despite not directly affecting the catalog or the presets, I recommend having a backup of these and of course your original photographs before any procedure for security reasons.

How to set Lightroom Classic preferences (adobe.com)

yes they all work great except lightroom classic

that sounds horrible. Possible, that your setup is too weak for LR? Do other applications run properly? (Photoshop / Premiere)