Got a notification to upgrade, so I did...I have 3 projects under my solution, 2 of which use Telerik WinForms...one project updated just fine, the other fails...I get the following error message:

Error executing custom action
Telerik.WinControls.VSXActions.UpdateReferencesAction: Object
reference not set to an instance of an object.

after which, it removed all Telerik references from the project in which it failed...now it gives me the option to 'Convert to Telerik WinForms Application' which I tried...then I selected the GridView, which auto selects the other ones that are needed...I click finish, and I get the exact same error as above.

thoughts?

Hello Adam,

The issue you are experiencing looks like one we already addressed in a previous release. You can read more on how you could resolve the issue on your side in to following forum thread:
Q2 2011 Upgrade Wizard Issues Resolved

Let me know if that helps.

All the best,
Andrey
the Telerik team

thanks, I saw that post and tried doing everything on there, but I couldn't seem to get the extensions update to install, there was no error, it just 'hung' when it went to install via the extension manager...ended up that, despite me having admin rights on my own computer, I still had to run VS2010 in 'Admin mode' to get the update to install properly. Now that I did that, it works just fine..