Problems when adding custom control dll into my Form(WinForm)

Adding the custom control from my toolbox into a form works fine, however when I try to build the project I'm getting this error; "The type or namespace name "CustomControls" could not be found", but when I check the project's "References", I can see th开发者_如何学编程e CustomControls located at the very top.

Change your project to target the full version of .Net 4.0 (not the client profile).

Also check that the custom control DLL is not platform x86 only, while you are using 'Any CPU', I once had some weird errors because of this. As for the warning you get, the following might solve your problem Where did System.Design go?