Why does this happen?

You’re probably going to get better help in the forum covering this plugin. It’s currently on life support as the original maintainer stopped supporting it. Hopefully the official release makes the 4.25 release!

Anyway, looking at the forum it seems only support for 4.24.1 has been created? Luoshuang's GPULightmass - #468 by Situx - Rendering - Unreal Engine Forums

we have installed the UE4.24.2and the GPULightmass 4.24
When we try to build a scene the GPU Renderer crashes with the message “Illegal Memory access was encountered”

This happens to me with all versions of Unreal, help please.