Error 8, unreal revision control not connected

hi @OleszykYt You need to be running as Administrator.
UEFN will not install correctly from Launcher on any Windows 11 (eleven) version needs to run Elevated "Run As Administrator - General / Issues and Bug Reporting - Epic Developer Community Forums

When you start UEFN you must be running via EP GL “Run as Administrator” for everything

You cannot do anything without “Run as Administrator” for everything

You may have to uninstall UEFN and install as described above