After runnnig the update from macOS Catalina 10.5.5 to 10.5.6 on my iMac (Retina 5K, 27, Late 2015) InDesign 15.1.1 crashes while starting. The same installation (InDesign 15.1.1) is still running without problems on my MacBook Pro (Retina, 13, Early 2015, macOS Catalina 10.15.2).
Is there any issue known about trouble with that combination?
Sorry to hear about your experience. Does InDesign crash while working on a specific file or performing a specific action?
Please try booting the system into Safe Mode (https://helpx.adobe.com/in/x-productkb/global/start-safe-boot-mode-mac.html) and check how it works there. It starts your system so that it performs certain checks and prevents third party software/ services from automatically loading or opening. If it works fine in Safe mode, then there is some third party service or application like antivirus, plugins or web extensions which are conflicting with the InDesign.
If that doesn't help either, login to root account (https://support.apple.com/en-in/HT204012). Check how application works there. If it works fine there, then it could be related to permission errors. Follow these steps to repair permission errors:
Go to Terminal (Go > Utilities > Terminal.app)
Execute the following command on terminal to provide permission:
sudo chmod -R 777 /Users/<user>/Library/Application Support
If nothing helps, then we need to troubleshoot this on a live session. Please head here (https://helpx.adobe.com/support.html) and select the chat button in the lower-right corner of the page. We can help on a live session that way.