Has anyone ever found a solution to either of these problems:
When entering any design mode in Visual Studio 2010 (WPF, EDMX, Silverlight, Reporting, etc) I see a message in the status bar like
Loading toolbox content from package Microsoft.VisualStudio.IDE.Toolbox.ControlInstaller.ToolboxInstallerPackage '{2C98B35-07DA-45F1-96A3-BE55D91C8D7A}'...This locks VS for about a minute everytime.Telerik toolboxes have many duplicate controls.
Toolbox doesn't show any items when expanded. I think this is because it has too many controls in it.
I believe all of these issues to be related. I think when #1 happens, duplicate controls are added to some toolboxes, which eventually causes #3 to happen.
I'm sick of this and I'm pretty sure it's caused by Telerik's "Rad" stuff. I have 2 dev machines that never did any of this until I installed some rad controls.
I have experienced this once before and the problem was easily remedied, but I think it would be on Telerik to figure out a permanent solution.
It seems that when you update your controls, it maintains instances of the installs (the different versions) Example
I'd assume that if you have installed many updates, the toolbox itself has experienced some kind of issue regarding the variety of versions and thus led to all the problems described there. It's also worth nothing that when new revisions (the Q1/Q2/Q3/Q4 releases) come out, if you update the tools inside VS, your computer may still think the older version is installed on your computer. (Go check "Add/Remove" programs from your control panel and see if you have the latest release installed like here).
When I fixed this problem on my computer I uninstalled the old release (which was a Q1 release). This got rid off all the updates that I had installed for Telerik during that quarter. I then installed the Q2 release (which was the most recent download from the site) and simply loaded up my apps and converted them to the latest release when prompted.
Hit me back with an update if you try the reinstall of the most recent release from Telerik.
Take a look at this post I made on the Telerik website (post on Sep 7th near the bottom)
In a nutshell, it may be something else that is crashing the Toolbox cache initialisation process (in my case it was WCF RIA Services Toolkit April 2011). Once I got rid of that it was all back to smooth sailing. I was lucky in that I only had the RIA toolkit installed for testing so I could remove it without impacting my workflow. Not sure what you'd do if you needed the RIA toolkit though...
Anyway, it's worth looking in to!
Oh, and I agree entirely that the issue sucks big-time. I was getting to the point where I had to wait 5 minutes each day for the IDE to get ready...that's a lot of hours of wasted time over the past few months!
I know this is an old question, but maybe my answer can help people with the same problem...
I recently installed the Telerik RadControls 2012 Q2 for Silverlight and encountered the same problem. Every time I opened a new instance of Visual Studio the Telerik controls duplicated until the toolbox crashed. In search for an answer I stumbled upon the forum Spoida mentioned. In my case, the WCF RIA Services Toolkit (September 2011) was causing the problem. Unfortunately I need the toolkit so removing it was not an option.
After another exhausting marathon of google searches I stumbled upon another solution that does not require you to delete the WCF RIA Services toolkit:
REMARK: These steps include deleting keys from the registry. Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. Modify the registry at your own risk.
1) Open your registry and delete the following keys:
Toolbox registry key under HKLM\SOFTWARE\Microsoft\Microsoft SDKs\Silverlight\v4.0\AssemblyFoldersEx\Ria Services v1.0 Silverlight Libraries
Toolbox registry key under HKLM\SOFTWARE\Microsoft\Microsoft SDKs\Silverlight\v5.0\AssemblyFoldersEx\Ria Services v1.0 Silverlight Libraries
When you are working an a 64-bit machine, you'll need to insert WOW6432Node after Software in those paths.
2) Now find the ToolboxControlsInstallerCache and ToolboxControlsInstaller_AssemblyFoldersExCache registery keys under
HKCU\SOFTWARE\Microsoft\VisualStudio\10.0 and delete them.
3) Open Visual Studio and reset the Toolbox.
After performing these steps everything worked as expected, and there were no duplicate controls in the toolbox!
In Visual Studio 2010, went to Tools menu -> Add-in Manager and unchecked the "startup" column for "Telerik OpenAccess" and "Telerik OpenAccess DSW" and lag in the startup went away. There might be other Telerik add-ins you should disable to see if that helps. In this case, I have their OpenAccess installed but not actually using it.
来源：https://stackoverflow.com/questions/7402569/telerik-visual-studio-2010-toolbox-maddening-problems