Today I spent half a day fixing this issue. It only affected the 2019 version as I could work on the 2018 version. Nevertheless thanks to this thread I have a solution: Adobe Premiere Pro could not find any capable video play modules. Please update your video display drivers and start again.
Apparently Premiere 2019 tries first to access the onboard graphic card of the CPU. I have a Intel Xeon and a 1080 ti. Drivers and everything up to date so I had to uninstall the onboard gpu with this tool: Display Driver Uninstaller Download version 22.214.171.124
After restarting Premiere worked again!
Wow! Great. Thanks for the info.