Please do a full **clean** re-install:
- move any valued save games elsewhere
- "uninstall" in Steam-Imperator
- manually delete both the Steam/SteamApps/common/Imperator AND Documents/Paradox/Imperator folders
- re-install game in Steam, run a Steam Verify when done.
- add imperator.exe to the exceptions list of your antivirus app; ESPECIALLY if you have Windows Defender, add it to the Ransomware "Apps Allowed Through" list.
- start the game with no mods active and test
In particular you need to make sure there are no files or folders left under either the Steam Imperator or Documents Imperator locations, before installing again.
That should do it for you!