First of all uninstall the Epic Games Launcher. Now install a new version of the download section for EGL.
Next try and verify the games from inside the new launcher.
Next add the game to the Windows Defender exclusion List as this might be wrongly seen as malware see post.
urc.exe and urc.dll get flagged as Malware from Microsoft Defender - General / Issues and Bug Reporting - Epic Developer Community Forums
Then add Marvel_Win64_Shipping.exe to the exclusion list
then “run as Administrator” Windows Command shell
Restart your PC to check and fix errors.
This may take several attempts tofix all the errors