Studio1 v 4.1 doesn't add the vst3 version of the plug in, but the vst2 version is found and loads fine. The dll is in the correct location in the plug in manager file locations and it is not blacklisted. I have re-scaned countless times At present all the McDsp presets are for vst3 only, so although I can use the vst2 version its not full fledged.