Hi ! I recently just format my HD so I needed a fresh installation of sonar. 
 
I did install sonar and after my VST. I don't understand why some of my vst doesn't show (And it was working perfectly before)
 
They are on the right folder, I tried to move to a new folder and add the folder to sonar and still doesn't show.
 
So, some show and works (Like superior drummer, ReFX Nexus, etc..) and some doesn't (Kontakt 5, Battery 4, Omnisphere, etc..)
 
Thanks for your help !

No idea what version of sonar you are using so cant really tell.
have you tried running a reset/rescan of your plug ins ?

Hey ! Did that alot of time, I'm using Sonar X3e Producer

Anything that requires installation doesn't usually like it if you move it after it is installed. At least that has been my experience. The .dll ones don't seem to care. I would just add all the locations to plugin manager. It doesn't seem to care how many locations you have.

try going to preferences / Vst settings:
There should be an option to show/hide VST 2 plug ins, exc.
try that. it might be an issue with seeing your vst 2 plugins.

Thanks everyone, I figured out myself how to resolve this.
 
I just restarted my PC and all the plugins appeared :)