is such a problem that VS 2010 cannot correctly resolve the path to any of
our assemblies – we have reported this issue to MS and we are working
closely with them to resolve it as soon as possible. As a workaround
you can manually copy all our assemblies to the VS 2010 public assemblies
folder and everything will work as expected. In fact we face the same
problem with our Silverlight 3 assemblies, if you try to add manually them to the VS2010 toolbox you will get the same error. However,
our installation deals with this limitation by using registry entries.
There is also another problem that you need to know. If you
add our RadControls for Silverlight 4 assemblies to the toolbox and you also have our Silverlight 3 assemblies
installed you won't be able to drag any of our Silverlight 4 controls from the
toolbox due to an exception. Therefore, to make our Silverlight 4 assemblies add
to the toolbox and work properly you will have to perform the following
1. Uninstall Telerik Silverlight 3 controls
2. Manually copy our Silverlight 4 assemblies to the VS Public Assemblies folder and manually add them to the toolbox
We apologize for this inconvenience, this is why we posted that we don't have VS2010 toolbox support in our SL4 related blogpost.
But still this is only a beta for both VS2010 and Silverlight 4 and we can assure
you that we are working closely with Microsoft to resolve those issues.
If you think that these workarounds are too much trouble you can still
try our controls without toolbox by just writing XAML.