Please try to deactivate every other 3rd party module ( by setting the <disabled>True</disabled> line in their lines in the DLL.XML and EXE.XML ), except bglmanx.dll in DLL.XML and couatl.exe in EXE.XML, and test it.
Then proceed by exclusion, and reactivate one by one, testing separately with relaunching P3D each time, until you find the offending one.