Cook Fails Due to Incombatible or Missing Module

The game builds fine in the editor if I do File>Package Game>Win64.

However if I run from the command line (or from Unreal Front End):

RunUAT.bat BuildCookRun -project="{project path.uproject}" -nop4 -platform=Win64 -clientconfig=Development -cook -allmaps -build -stage -pak -archive -archivedirectory="{build directory}"

I get the following errors:

LogInit:Warning: Incompatible or missing module: UE4Editor-BikerGangManager.dll
LogInit:Warning: Incompatible or missing module: UE4Editor-VictoryBPLibrary.dll

This is the log from that build: Failed Build Log

However, if I run with the following flag:


Then the build proceeds as expected. This produces this log: Successful Build Log

It is a weird flag that I can’t find documented anywhere which makes me nervous. Why do I need this flag? What is it doing?

Edit: Attached Build Logs

Edit 2: More Information

I have tried running the command on the build machine (which hasn’t launched the editor) and with or without the UseDebugParamForEditorExe flag I get the same error (about incompatible/missing modules).


Could you please provide your logs from your project’s Saved->Logs folder after the packaging process fails?

As far as what the -UseDebugParamForEditorExe flag does, I am investigating this now and will let you know once I have information.

Rather quick turnaround, but it appears that the -UseDebugParamForEditorExe flag adds the -debug flag to the cook on the fly server, which makes it use the debug ddls.

I’ve attached both the successful and failed logs from the build process - but there doesn’t seem to be much useful information in the failed one… Thanks for the info on the flag, clearly don’t want to be using debug DLLs.

Thanks for updating the post with the logs, I’m looking into this further now.

Are you using any external plugins?

Rama’s “Victory Plugin”

Have you tried packaging without that plugin to see if it makes a difference? It’s possible that it can cause a conflict.

This isn’t very practical advice - this would involve going into various blueprints to find any nodes that come from that plugin and rewrite that blueprint to not depend on it. Let’s assume that does fix it, what would be our next step given that we want to use that plugin?

I’m asking because if the plugin being removed resolves the issue, then you can start to narrow down exactly what the cause is. If that does fix it then you’ll need to communicate with Rama to try and figure out why the plugin would be conflicting with your setup (again, may not be the case, but I’ve seen it occur quite a few times so it’s worth testing).

Another suggestion if you are using C++ would be to regenerate your project files and build the solution again.


I am marking this topic as resolved for tracking purposes, as we have not heard from you in a few days. If this issue persists, feel free to respond to this thread. For any new issues, please create a new Answerhub topic.

Have a great day

For anyone who’s just now running into this, here’s what could be happening.

  • You haven’t built the Editor yet. This can happen if you deleted Intermediate and you only have the binaries necessary to make the game run.
  • You’ve built a debug version of the Editor. Unless you rebuild with a Development or Shipping configuration, you’ll need to add -UseDebugParamForEditorExe to your cooks so it understands to use the debug binaries.

Communicating with Rama just means another page added to a 149-page forum and him suggesting that the answer is somewhere in the previous 149 pages…