Lightroom Classic only opens in background

Please see here: P: LrC 12.2.1 fails to start/launch or is extremel... - Adobe Community - 13673512

If this doesn't help please give us more informations about your system, including the following:

• Adobe product and version number
• Operating system and version number
• The full text of any error message (s)
• Computer hardware, such as CPU; GPU; the amount of RAM; etc

Maybe you can post your Photoshop system info. In Photoshop goto Help > System Info and hit the copy button. Then paste the entire informations into this thread. Thanks. The above info will help to solve your problem.

... I have uninstalled/reinstalled and have tried various other "solutions" on the web...

By @danielle_7861

Do you have do a clean reinstallation? If no, Please follow the steps below:

• Backup all personal data, like templates, presets etc.
• Uninstall everything cc including preferences,    https://helpx.adobe.com/creative-cloud/help/uninstall-remove-app.html
• Then uninstall the cc desktop app,    https://helpx.adobe.com/creative-cloud/help/uninstall-creative-cloud-desktop-app.html

• Clean your computer of cc files per   http://www.adobe.com/support/contact/cscleanertool.html
• Restart your computer (don't skip this)

• Reinstall the cc desktop app,    https://www.adobe.com/creativecloud/desktop-app.html
• Use the desktop app to install your cc programs/trials
• Restore your personal data.

If you're unable to install the cc desktop app at this stage, use an administrator account (solution 4 here, https://helpx.adobe.com/creative-cloud/kb/creative-cloud-missing-damaged.html)

Using Windows File Explorer, bring up the folder your catalog is stored on, does a lock file exists? Can you share a screenshot of that?

• https://helpx.adobe.com/lightroom-classic/kb/lightroom-error-catalog-cannot-be-opened-lrcat-lock.html