5.8 not compiling. Says needs to build from source

[CarlosDorietyJr]

Tried the source folder and the 5.8. The engine thinks its an older plugin as if it wasn't compiled for 5.8

Steps include putting the plugin per instruction to the same folder as the project exe to open unreal, and within a folder called "plugins"

Start the engine, says that many things are from a previous version and to build.

Does not work

I tried to use the source folder and it will let you open unreal, but when you enable the plugin and restart, you end up in the same loop.

UnrealEngine Version:
UE5 5.8

[ReazenCode]

Same issue

[ruyo]

Hi.
It works without issues in my environment.
Are you using a self-built version of UE5.8? If so, you need to build the plugin.
thanks.

[penyparker]

same here too with Latest Visual Studio Updated

[SeverinRoman]

Disabled the plugin until the update (

[ReazenCode]

For anyone who's unable to compile, double-check that you're using the 20260622 release. My silly mistake was that I had downloaded 20260513 ( https://github.com/ruyo/VRM4U/releases/tag/20260513 ) instead. Even though there's a 5.8 version of the plugin in that release, it apparently doesn't work anymore. You need to download the latest release. https://github.com/ruyo/VRM4U/releases/tag/20260622

[CarlosDorietyJr]

For anyone who's unable to compile, double-check that you're using the 20260622 release. My silly mistake was that I had downloaded 20260513 ( https://github.com/ruyo/VRM4U/releases/tag/20260513 ) instead. Even though there's a 5.8 version of the plugin in that release, it apparently doesn't work anymore. You need to download the latest release. https://github.com/ruyo/VRM4U/releases/tag/20260622

This was indeed the fix, 513 doesn't seem to compile up to the current 5.8. As soon as you use version 622. it works and compiles.

But it still does not show IK retargeter. Reimported and full deleted just to make sure. I even tried it in a clean project, but ever since 5.7. I haven't seen the IK retarget tool. It does not generate it on import. It also seems to have a hard time auto naming bones to match the mannequin, but that could be my fault.

[AgentOttsel]

I was having issues compiling the plugin with my source build of UE5.8, getting "redefinition" and "multiple initialization" errors complaining about VRM4U_MaxBoneWeight being defined in both VrmConvertModel_Description.cpp and VrmConvertModel.cpp. I was a tad confused, because they are defined in cpp files, which shouldn't be aware of each other. Then I remembered that Unreal supports unity builds (not to be confused with the Unity Engine), a feature which joins all the cpp files into one for faster compilation times (sometimes with weird side effects like this, unfortunately).

So I went to VRM4ULoader.Build.cs, found the line that said:
//bUseUnityBuild = false;
and changed it to this
bUseUnity = false;

Notice that I didn't just uncomment it, but also updated the property to match its current name.

Not sure if this is the same issue that you guys are having, but hopefully this helps! Perhaps not using unity builds should be the default setting in VRM4U, otherwise it'll just use whatever setting your project has, which would explain why it currently compiles correctly in some projects, but not others.

[gapspt]

Need to fix something in the GitHub releases then, because https://github.com/ruyo/VRM4U/releases/tag/20260622 is not appearing in https://github.com/ruyo/VRM4U/releases - meaning most people will be downloading the 513 instead.

[ruyo]

Hi.
I haven't encountered any issues in my environment.
I've kept the Unity build enabled, and it hasn't hindered my local development.

If you do run into any problems, please report them as a new issue.
thanks.