Lightroom Classic no longer opens on my iMac running macOS Big Sur.

If none of the other suggestions work, you can unistall tand reinstall the application, but do not delete your Catalog.

Warmly/j

Hi,

We're sorry about the trouble with Lightroom Classic. Would you mind sharing the version of Lightroom Classic you're using along with the exact version of Big Sur you're working on?Are you getting an error while trying to launch the app or nothing happens when you try to launch it?

If the steps suggested by @GoldingD don't help, please ensure that Lightroom Classic has the necessary permissions on your Mac by following the steps suggested below:

1. Go to the System Preferences for your Mac, then Security and Privacy, then select the Privacy tab.

2. Then select Accessibility from the list to the left & check if Lightroom Classic is added to the list with a check mark in front of it.

3. If Lightroom Classic is not a part of the list, please add it by unlocking the window first using the lock at the bottom left, then clicking the + icon & navigating to the Applications folder.

4. Also, grant permissions to Lightroom Classic under Full disk access located in the same list as Accessibility.

5. Once done, restart the Mac & check if it helps.

If the issue persists, you can try to reset the preferences of Lightroom using the steps mentioned here: https://adobe.ly/2JSym5e

Please backup your presets prior to resetting the preferences.

Let us know how it goes!

Regards,

Nikunj

Did it  open previously?

If so, did you force it to quit as opposed to a nice close?

Or did it crash?

If either, see:

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

note that you might not get the error message mentioned.

Be very very careful to not delete the catalog

And if LrC previously worked, but you do not think you forced quit, or crashed, look anyhow.