Fix for this issue is now available in the latest update of InDesign 2021 – that is, InDesign 16.2.1
In the Creative Cloud Desktop application, click on the Updates section on the left. You should be able to see the Update available for InDesign. Please update your InDesign application to this version to try out the fix.
Let us know in the comments section if you still face this problem.
Adobe InDesign Team
An error occurred while saving the commentSinead commented
Hi there I am also having this issue. I have uninstalled and then reinstalled and it's still happening.
Can you please fix ASAP as I have deadlines and work to do!