first thing you could try:
 Make sure that InDesign is not running; check the Task Manager of your Windows 10 system.
 Save or rename the InDesign cache and the InDesign preferences folders.
 Remove InDesign cache and InDesign preferences
 Start InDesign 2020 version 16.0
To access and see the folders where cache and preferences live, activate "Invisible Elements" in the "View" tab of your file explorer in Windows 10. On your German Windows this is tab "Ansicht" and option "Ausgeblendete Elemente". Enable "Ausgeblendete Elemente" so that folder AppData is showing up.
To navigate to the InDesign preferences folder:
[UserName] > AppData > Roaming > Adobe > InDesign > Version 16.0
To the InDesign cache folder:
[UserName] > AppData > Local > Adobe > InDesign > Version 16.0
If removing preferences and cache will not help:
Uninstall and re-install InDesign through the Creative Cloud Desktop Application.
( ACP )
I've followed the steps but unfortunately InDesign still crashes.
All other programs in the Creative Suite work perfectly.
What else could i try?
I suggest you unistall InDesign, using the drop-down menu in the Creative Cloud app, and reinstall InDesign again. If that doesnt solve the problem then unistall it once again and then run Adobe Cleaner before reinstalling InDesign again.
Here's a link to Cleaner: https://helpx.adobe.com/uk/creative-cloud/kb/cc-cleaner-tool-installation-problems.html
sorry to hear about your experience. Please try the troubleshooting steps given on this help article(https://helpx.adobe.com/in/indesign/kb/crash-on-launch.html) & let us know if it helps you out.
I've followed each and every step but InDesign still crashes.
I also tried to install a previous version and this crashes too on startup.
If I start InDesign as "administrator" strangely it starts properly.
But after opening it freezes completely and I cant do anything.
I can only then quit the task within the task manager.