Is Guitar Rig 4 no longer part of the Sonar FX collection?   Did I miss something?
 
I have been using Guitar Rig 4 in its Sonar version since it first shipped with Sonar (X1 I think).   I've been using it through X2 and X3 but today I tried to open it on an older project track (it was inserted some time ago) and it told me it was a demo version of GR4 and I had to activate it. 
I duly opened the service centre and put in the serial number I got with X1 (the only one I have).  It accepted the serial number and said 'all products activated' but when I went back to the project it just did the same as before, said it was a demo and asked me to activate.  Tried again, same result.  
Tried reinstalling from the Native Instruments site with restarts etc.     Then tried reinstalling the update from the X3 bundle but still the problem persists – it only opens as a demo version and asks me to activate (or buy the full version).  I notice it's not mentioned in the Platinum lists in the command centre.
 
I'd be grateful for any advice.  I did a forum search but found nothing.    Thanks.

Is this one of those things where you have to register the software in the standalone version first?

Guitar Rig 4 hasn't been part of SONAR for some time. This is something you may need to work out with NI. Note that you'll need the 1.1 update.

Try doing the authorization during a Sonar session that was launched with the EXPLICIT option Run As Administrator, which gives Sonar and plugins within Sonar higher execution token privileges than you get by running Sonar without setting that launch option.
 
Please note that Run As Administrator is NOT the same thing as having a Windows user that is of Administrator type.
 
To launch Sonar once with Run As Administrator, right-click on the launch icon for Sonar, then click on Run As Administrator.
 
To permanently set the properties of the launch icon for Sonar to Run As Administrator, right-click on the launch icon for Sonar, then click Properties, then click Advanced, then check the box for Run As Administrator, then click OK, then click Apply (you may have to additionally click 'Continue' to allow that change), and from then on, Sonar will launch with Run As Administrator.
 
Bob Bone
 

+1 to Bob's advice. GR4 LE was bundled with SONAR X1, and I forget now how I initially activated it. I am pretty sure I activated it initially in Stand-alone mode, and that I explicitly launched it as administrator when I did (allows programs to make required registry changes).
 
After that point, I would recommend closing and reopening SONAR (just to free all memory it is using), then go into Preferences->File->VST Settings and under Scan options, check both Rescan failed and existing plugins... manually scan ("SCAN" button) and when finished, uncheck the two rescan options and Apply/OK out (you do not want to leave those two checkboxes enabled as this is a one-time thing).
 
If NI says all things are activated, you may simply need to do the rescan mentioned above.

Just bumping this to apologise to those who replied and I didn't acknowledge  - I did look back in on the thread before there were any replies and thought there hadn't been any, then I've been a bit busy with other stuff and forgot to check back.  I'll try the solutions offered.  Thanks for replies.