I recently took delivery of Sonama's Drumcore4 , the USB Flash drive version. Installed on my computer with no problem (OS Windows10) But, the plugin is not being recognised by Sonar X3  when I run a scan . I believe the folder I need to 'add' to VST scan paths  is c:\programfiles\commonfiles\vst3 , which unfortunately I cannot locate. Any ideas?
 

Have you got the latest version, you may need to update from the web-site. Its been quite problematic and there have been a lot of updates and fixes. The multi-out function still does not work in Sonar but other than that its working for me in Platinum.

Early VST3 implementation in Sonar was a bit flakey too. I am not sure when it got sorted.