Mission Control won't open after updating to Catalina

Hello Robin.O.

Welcome to Apple Support Communities. We understand that after upgrading to macOS Catalina that Mission Control no longer opens. We’re happy to help.

Please try the steps here: How to use safe mode on your Mac - Apple Support Are you able to use Mission Control as expected?

We also recommend the steps here: How to test an issue in another user account on your Mac - Apple Support These steps will allow us to isolate the cause to either your user profile or the Mac.

Let us know the results.

Take care.

Hello Robin.O.

We're glad to hear that it is working now.

Take care.