This issue has been resolved in the latest InDesign version 15.1
Adobe InDesign team
An error occurred while saving the commentMarcel commented
Okey I finally solved this after wasting two hours. Here's how:
> Open the Terminal via spotlight. It says something like this:
( in this case, jonnyrakete is your username )
copy and paste the following commands and hit enter, they will work unlike the **** adobe provided in their help article. But don't forget to replace jonnyrakete with what's written in your terminal. Hint: if the terminal gives you no response at all, it worked. If there's a message you did something wrong.
sudo chmod -R 777 /Users/jonnyrakete/Library/Preferences/Adobe\ InDesign
sudo chmod -R 777 /Users/jonnyrakete/Library/Caches/Adobe\ InDesign
if your terminal gives an error now, type in these two commands:
sudo chmod -R 777 /Users/jonnyrakete/Library/Caches
mkdir /Users/jonnyrakete/Library/Caches/Adobe\ InDesign
sudo chmod -R 777 /Users/jonnyrakete/Library/Application\ Support
enjoy your day if it worked!