If you can not get past this section, you can setup the installer to skip the permission step and setup the proper permissions manually. To do this you would use three flags passed in on the commandline: SKIP_PERMISSIONS_INSTALLFOLDER=“1” SKIP_PERMISSIONS_APPDATA=“1” SKIP_AUTOLAUNCH=“1”
Instructions for doing this can be found in the answer to this thread: Unreal Engine Setup Wizard ended prematurely - Programming & Scripting - Epic Developer Community Forums