Project is not valid after 'Saving As"

I was working on my level, which has been working fine throughout. I decided to ‘Save Current Level As’. Once I did and pushed the changes I got the message "Project is not valid see message log for detail.

The log seems to reference a lot of lights and player spawns.

There doesnt seem to be a way to go back to an older version. Any thoughts? I was just waiting for the 21/90 day rule to publish after working on it for weeks. DOH

Just found out that I can get rid of some of the entries in the message log.
By clicking on an entry in that message log it get’s shown in viewport. I then copy the selected and delete it, only to paste it again. So it was placed in uefn and not in Live mode. It then disappears from message log after updating it by trying to upload to private or by trying to start Live session.
I am now down to about 700/1400.
And I noticed that the message log contains entries from both of my map backup saves.
Might just delete the earlier backup.

I don’t know if this is helpful to you at all, but worth a try I guess.