After a whole set of attempts, some solution came out 😃
- I've set the switch for Origin cloud saving profile/... to 'on'
- Logged out, closed/killed all Origin tasks in the task manager
- Deleted the folders as described above
- Uninstalled Origin Client (was located on on my D-Drive) but kept my games installed on this drive.
- Restarted and installed the client on the OS (C-)drive
- Logged in and opened my games library
- In 1 second all games were up-to date (green check mark - downloaded and installed) So, it looks like the issue before was probably related to an incomplete handling of downloaded & installed files.
=> No warnings (on old version/close the windows message/ ... ) anymore when starting one of the updated games. Settings & key bindings were as saved before.
=> Downloading a new game started without an error message (installing and game start is for the upcoming night)
Thanks for the tips & suggestions!
MVa