Your installer is failing to setup folder permissions. latest version of installer supports command line parameters that will allow you to bypass portion of install process that sets up these user permissions but you’ll have to manually apply proper permissions to install and programdata folders. I have outlined process below.
If your installer log has one or both of these failures, try workaround outlined below
CustomAction QtExecSetPermissionCmdLineRun returned actual error code 1603
OR
CustomAction QtExecPermissionAppDataCmdLineRun returned actual error code 1603
Workaround
- Download latest Unreal Engine Installer
- Run installer using following commandline(replace C:\UnrealEngineInstaller.msi with path/name of installer you downloaded): msiexec /i “C:\UnrealEngineInstaller.msi” SKIP_PERMISSIONS_INSTALLFOLDER=“1” SKIP_PERMISSIONS_APPDATA=“1” SKIP_AUTOLAUNCH=“1”
- Set user permissions on install folder. This can be done a number of ways but simplest may be to run this commandline(replace C:\Program Files\Unreal Engine with your selected install location): icacls.exe “C:\Program Files\Unreal Engine” /grant “BUILTIN\Users”:(OI)(CI)F
- Set user permissions on ProgramData folder. This can be done a number of ways but simplest may be to run this commandline(replace C:\ProgramData\Epic with location of your Epic AppData folder): icacls.exe “C:\ProgramData\Epic” /grant “BUILTIN\Users”:(OI)(CI)F
- If steps 3 and 4 completed successfully, try launching using Unreal Engine shortcut on your desktop or in your start menu