Lightroom classic v15 corrupted catalog

I first noticed an upgrade on the Lightroom mobile v11. So upgarded on phone and tablet. Did a few edits on a few photos testing the enhance snow and blemishes new feature. All my photos in mobile (ie Cloud) are sync with smart collection to actual photos in the LrC which I keep running 24x7.
Upgraded the LrC the following day to v15. It upgraded the v14.4 catalog but says the catalog it just upgraded to be corrupted.  On relaunch it tried to repair and upon repiared and relaunch again it still report the same problem ie need to repair.

I reverted to LrC 14.4 and 14.4 catalog launches without problem but reported newer version of metadata. I was able to stop the sync and can use the LrC 14.4 without problems. 

I optimise the v14.4 catalog and reinstall v15, however same problem persists.

Need help to get V15 running. 
Either Adobe update the v15 to cater for this use case or provide instructions to remove all the new edits using the new features I did with Lightroom mobile V11.
Preferably the option for V15 to recognise new metadata (to the new features) and perform an upgrade without corrupting the catalog it upgraded. 

The later option is also ok if does not require me to remember which photos I use to test the new features which I did a fair number.
LrC is Windows. LrMobile is Android.