Hot Reloading Game Modules

Hi there

Recently I wanted to rename my UE project (which has C++ sources). As a lot of people seem to be having trouble renaming their projects, I chose a differen approach, in where I declared my previous PrimaryGameModule to be a normal GameModule and introduced a new PrimaryGameModule with the new name of my project. This way packaging the project correctly gerenates a .EXE with the new name.

However, I noticed, that hot reloading my now secondary game module does not work anymore. Since pretty much all of my code is in the secondary game module, it is really painful to restart the editor each time. When I check the list of modules currently loaded in the editor, I can find my new primary game module, as well as the secondary module. However, the “Unload” and “Reload” buttons are missing for the secondary module.


Is this a known issue/limitation of the Editor, or am I just doing something wrong? Apart from the hot reloading everything works perfectly with the new setup of using the previous primary module as a secondary module.


When I press the “Recompile” button, I get the following error in the console, if this is of any help:

Recompiling Arena...
Launching UnrealBuildTool... [C:/Program Files/Epic Games/4.9/Engine/Binaries/DotNET/UnrealBuildTool.exe UE4Editor -ModuleWithSuffix Arena 4689 Win64 Development -editorrecompile -canskiplink "C:/dev/Supremity/Supremity.uproject" -rocket  -rocket]
CompilerResultsLog: New page: Compilation - Oct 21, 2015, 4:58:44 PM
CompilerResultsLog: Info Performing full C++ include scan (hot reloading a new target)
CompilerResultsLog: Info Creating makefile for hot reloading UE4Editor (no existing makefile)
CompilerResultsLog: Info Compiling game modules for hot reload
CompilerResultsLog: Info ERROR: One or more of the modules specified using the '-module' argument could not be found.
LogMainFrame: MainFrame: Module compiling took 2.266 seconds
Warning: HotReload failed, recompile failed
Warning: RebindPackages failed because the compiler could not be started.

You have also “module” command in console to load and unload modules. Fact that Unload and Reload is missing most likely means module is not loaded at all, but check “module list” command

The module is loaded, otherwise the entire game wouldn’t work, as all of my game logic is inside that module. Just to verify, the “module list” command contains the following line:

Arena [File: …/…/…/…/…/…/dev/Supremity/Binaries/Win64/UE4Editor-Arena-8631.dll] [Loaded: Yes]