I just want to leave this as a note since I already reinstalled the affected client:
I recently upgraded a client from the 1809 to the 1903 release. After the upgrade the CCS Suite was “partly” removed. The windows installer entries still existed and everything in the program files folder but the application did not start anymore and also removal and reinstall failed with MSI exit code 1603 (right at the beginning).
Please do not open a ticket for this because as I said: The client has been reinstalled but maybe someone else is facing this issue.