I just installed sonar from the command center, without any errors. 
My sonar platinum is installed in the same folder as x3, they share vst plugins. 
In general Ive experienced some problems with vsts, sometimes sonar picks the 32 bit versions instead of 64 bit, one vst had delay compensation turned off etc.. but vst is a problem in general since they tend to install themselves in 5 different places on the drive, sometimes I have to manually move the correct ones to sonars vst folder. 
Ok, if my problems are not normal my guess would be to reinstall everything.