There is no standard, standalone offline installer for Unreal Engine 4.27 available to general public users

2. The editor crashes on startup with "RHIInit failed"

  • Run Setup.bat (Windows) or Setup.sh (Linux/macOS) in the repo root to download dependencies. This requires internet.
  • Run GenerateProjectFiles.bat and open the generated solution in Visual Studio (Windows).
  • Build the UE4 solution (e.g., Build UE4Editor Development Editor).
  • After a successful build, package the built Engine folder (Engine/Binaries, Engine/Content, Engine/Plugins, Engine/Source compiled artifacts) into an archive (ZIP/7z) or copy the entire Engine directory to external storage.
  • On the offline target machine, extract the Engine directory to a path (for example C:\Program Files\Epic Games\UE_4.27). Ensure the same Visual C++ runtimes are installed (you can include their installers).
  • Optionally create shortcuts and verify by running Engine\Binaries\Win64\UE4Editor.exe.