Unreal Plugin stuck at 70%

Hi, I’ve created a c++ plugin to get sound volume levels from the bass library (www.un4seen.com) from blueprints.
I’ve included the bass dlls and the lib file in the binaries x64 dir, but when I load the unreal editor it’s stuck at 70%.
In the plugin dir I have a volumebw.h file:

#pragma once
using namespace std;
extern "C"
{
	__declspec(dllexport) int GetVolumeLevels();
}

and in the blueprintpluginbplibrary.cpp I have

UVolumePluginBPLibrary::UVolumePluginBPLibrary(const FObjectInitializer& ObjectInitializer)
: Super(ObjectInitializer)
{

}
int UVolumePluginBPLibrary::GetVolumeLevel()
{
	return GetVolumeLevels();
}

If i replace

return GetVolumeLevels();

with

return 0;

everything works fine. Can someone help?
Thank you very much.