The following guide is meant for users who've downloaded and built UE4 from its source code, which we've made available on GitHub.
If you download the latest Unreal Engine 4 (UE4) code, you might notice that there are no Visual Studio (VS) or Xcode project files included for compiling and running the engine or example games. You will need to run a script that generates project files for you to load:
Run the GenerateProjectFiles.bat file which is located in the main UE4 directory
You can run that script from any folder. (Make a desktop shortcut if you want.)
The project generator tool will analyze the module and target build files and generate new project files. This can take up to 15 seconds or so.
For VS developers, this will generate a UE4.sln file in the same directory. You will use this solution file to build and run UE4 games and programs. (For your first time compiling, we recommend building using the Development configuration with Win64 platform)
By default, we generate buildable projects for all available platforms that we detected SDKs for, so that you will be able to build and debug console and mobile platforms as well. If you want to generate projects only for the current platform you are running on (e.g. Windows.), run the GenerateProjectFiles.bat with the -CurrentPlatform argument. The project files will be a little lighter.
IMPORTANT: Remember to re-run GenerateProjectFiles.bat after syncing new code changes from source control. If you forget to do this, you will most likely run into problems when compiling or running your game.
If you make local changes to modules such as adding or removing source files, you should re-run GenerateProjectFiles.bat again. We do not recommend manually making changes to project files.