I have noticed that some of my plugins (Sonik Synth 2, Bandstand) don't work in Sonar now. Could it be that downloading the updates have corrupted Sonar? Maybe these plugins not compatible with Sonar? Funny, I had Cubase running on the same computer and these plugins were fine in Cubase!

Apply this to Platinum:
https://www.cakewalk.com/...ommended-for-Upgraders

Make sure windows update is up to date.

Otherwise let us know exctly what you mean by 'don't work' (the specifics).

Thanks..

^^^This. Reset and rescan solves most upgrade anomalies involving plug-ins. I believe most of this relates to VST3 support.

Yes, you're probably right I just did a clean install of Windows 7 over Windows Vista so I'm not sure if Windows has all the updates.

Older plug-ins may require SONAR be run as administrator.

All the third party plugins that aren't work in now are scanned without errors but just won't load and I get a error saying that may not be install correctly or that the plugin may be incompatible!

Assume you did RESET then a rescan.
Did you try Scook's suggestion?
You are running 64 bit Sonar I hope?
Post the full error messages here.

ronboy1952
 I get a error saying that may not be install correctly

This is often the clue that a plug-in requires administrator access to the registry. Old IKM plug-ins generally require administrator rights now. Right-click the SONAR icon and check the "Run this program as an administrator" option in the Compatibility tab of the properties dialog.