The fix for this issue is now available in the latest update of InDesign – that is, InDesign 15.0.2.
Please update your InDesign application to get this fix.
Adobe InDesign team
An error occurred while saving the commentAnonymous commented
Hey all -- I've tried to 'undo' and 'save' in V.16.0 and neither function is working consistently. The bug may not be totally fixed... I restarted the program and it's fine, but it's not dependable.