First delete that whole Paradox Interactive folder you see mentioned in that message.
THEN Please do a full **clean** re-install:
- move any valued save games elsewhere
- "uninstall" in Steam-EU4
- manually delete both the Steam/SteamApps/common/EU4 AND Documents/Paradox/EU4 folders
- re-install game in Steam, run a Steam Verify when done.
- add EU4.exe to the exceptions list of your antivirus app; ESPECIALLY if you have Windows Defender, add it to the Ransomware "Apps Allowed Through" list.
In particular make sure there are no files or folders left under either the Steam EU4 or Documents EU4 locations, before installing again.
THEN from the folder where eu4.exe is run launcher-installer-windows.msi and tell us what happens.
THEN run dowser.exe there as the Windows Admin user, and tell us what happens.