I just install my new Sonar Platinum upgrade from SONAR X3 and a bunch of VST dissappear Where they are especially  my KONTAkT and DIMENSION PRO?

Where are your kontakt and dim pro plugins (DLL's) stored?
Now check if they are in the file VST folder path in sonar preferences.
And then do this..
https://www.cakewalk.com/...ommended-for-Upgraders

Looks easy but didn't call it

I got my Kontakt but can't find my Dimension pro 
 

I think the default folder was C:\Program Files\Cakewalk
You can add that folder in the VST manager and then rescan. 
Or search your C drive for: Dimension Pro x64.dll (and add that folder in the VST manager, then rescan). 

It's just a matter of pointing Sonar's plugin-manager to the location of the "missing" plug-in's dll
 
There is no standard install location for VST 2.x plugins.
Pay close attention when installing... and you can select the desired (organized) location for the dlls.
If you just accept the default location for each individual plugin, you'll have dlls all over the place.