Files access problem

[3dRaven]

Perhaps the tips in this thread can help you

UnrealBuildTool Unable to open log file for writing because it is being used by another process

Oh, I had incorrectly skim read @OptimisticMonkey’s solution. When I read “Maximum number of parallel project builds” I stopped reading and assumed it was going to be setting MaxProcessorCount to 1 in BuildConfiguration.xml, which if was true would have pointed to a UE4 build bug. But this parallel build option in VS is a global setting, not per project. I didn’t even know such an option existed. Although I can understand why this would mess up Unreal Build Tool, it would be nice if you got a w…

It could also be windows defender that could be scanning in parallel. You can try to add your project and unreal engine (your version 5.3) to it’s folder scanning exceptions.