Just upgraded to 11.1 and am getting unexpected error on starting up across two different catalogs(have not tested more).
I downgraded to 11.01, and was able to open Lightroom Classic without a problem. Backed up the library, rebooted my Mac (iMac 5K Retina, 2017) running 11.6.1, reinstalled 11.1 and it seemed to run ok for about 2 days. This morning got the error report again and have downgraded to 11.01 again
Updates to the Adobe Photography Products were released today and contain a fix for this issue. Please install the update via your Creative Cloud Desktop App or your respective App Store. Note: You may need to refresh the Creative Cloud App for desktop software to show an update available. ([Ctrl/Cmd]+[Alt/Opt]+ [ R ]) For Mobile downloads, it may take several days for the update to appear in your respective App Stores. Thank you for your patience.