Lightroom Classic wont open. Says application not responding. I uninstalled and reinstalled. Still doesn't open.

Hi, the official troubleshooting steps are these, try them in order:

1. Check whether this is a known issue in the latest release of Lightroom Classic.

2. Install the latest Lightroom Classic updates.

3. Install the latest macOS updates (on macOS, graphics drivers are included with the operating system updates).

4. Restore preferences: quit Lightroom Classic, then start it while holding Shift + Option on macOS, and click Yes when asked if you want to Reset Preferences.

5. If you use third-party plug-ins, check with the plug-in manufacturer for an update, then disable them in File > Plug-in Manager and check if the problem is still occurring.

6. Start your computer in safe mode to rule out third-party extensions and utilities interfering.

7. If none of the steps above solve the problem, check user account permissions, as described in the document.

Full official document:

https://helpx.adobe.com/lightroom-classic/desktop/technical-support/performance-guidelines/lightroom-basic-troubleshooting-fix-most-issues.html