The fix is now publicly available in the latest InDesign update, 15.1.1
Please update to this latest version to get the fix.
Adobe InDesign team
An error occurred while saving the commentStuart Robertson commented
I have the same issue—which is a SHOWSTOPPER and has come at a REALLY BAD TIME—but version 15.1.1 does not show up in Creative Cloud update. How / where do I get v15.1.1?