Reproduction:
{System.IO.FileNotFoundException: Could not load file or assembly 'System.Windows.Controls.Data.Input, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.
[IO.FileName_Name]
Arguments: System.Windows.Controls.Data.Input, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
Debugging resource strings are unavailable. Often the key and arguments provide sufficient information to diagnose the problem. See http://go.microsoft.com/fwlink/?linkid=106663&Version=5.0.60401.00&File=mscorlib.dll&Key=IO.FileName_Name
at System.Windows.Controls.DataForm..ctor()}
Weird note: it does work in the VS/Exp. Blend 5 designers
Any ideas?? Workaround???
Found a very strange workaround: After I returned the SL version to 4, and re-returned it to 5, everything works! (?!?)
Anyway I'm sure recompiling the source-code of the SL TK targeting SL5 will help anyway.