Like many of you I have also been having problems with VS2010 freezing up during startup or when opening the toolbox related to this outstanding issue. Today I decided to do some analysis and see if I could determine the cause of the problem. I have two workstations I use to develop on and both have this same issue so I reviewed the installation of the Telerik products on both to see if I could find the problem. So far I have not been able to resolve the issue but I did find some issues that need to be addressed by the Telerik team.
Below is the summary of my analysis:
For my two machines, the first had previous versions from before the Telerik Control Panel was released and the second was a first time install of 2012.2 using the Telerik Control Panel.
The first thing I noticed on the older machine was that the Telerik.Web.UI and Telerik.Web.UI.Skins assemblies installed in the .NET 2.0 GAC were version 2011.3.1115.35 and the Telerik.Web.Design.dll was version 2012.2.815.35. I checked the newer machine's .NET 2.0 GAC and found that it only had the Telerik.Web.Design.dll assembly version 2012.2.815.35 installed. The Telerik.Web.UI and Telerik.Web.UI.Skins assemblies were missing. I then checked the .NET 4.0 GAC on both machines and found that the Telerik.Web.UI and Telerik.Web.UI.Skins assemblies were also missing from both .NET 4.0 GACs on these machines.
Based on this analysis I highly suspect that the 'RadControls for ASP.NET AJAX' installer and/or the Telerik Control Panel are missing the Telerik.Web.UI and Telerik.Web.UI.Skins assemblies from their .NET 2.0 and .NET 4.0 GAC install processes and perhaps other assemblies that depend on these assemblies were built with an incorrect version which could explain a tool initialization error.
To test this theory I removed the older assemblies from the one machine and then proceeded to install the Telerik.Web.UI and Telerik.Web.UI.Skins assemblies into the .NET 2.0 and .NET 4.0 GAC's from the Program Files Telerik folders on both machines.
I then ran the TelerikToolboxCleaner for all four product suites closing VS2010 as soon as it was loaded each time without opening any projects. Then I ran the Toolbox Configurator for all four product suites installing the Bin40 versions using the InstallFolder option.
Finally I launched VS2010 and opened a Telerik ASP.NET AJAX project to see if the issue was resolved. I restarted and opened the project and unfortunately the issue still exists.
Perhaps the missing assemblies are part of the issue and maybe some of the supporting assemblies that are loaded into the toolbox were built with the wrong version. It's hard to say but maybe this will help the Telerik team figure out why this is occurring.
I also tried this same process without installing the Telerik Silverlight products and it has no effect. Please let me know if there is anything I can do to assist you in resolving this issue as it is a huge productivity killer for me.