Visual Studio 2010 toolbox controls disabled or inactive

Question

I am trying to fix this from last two 2 or 3 days but failed. VS 2010 toolbox in asp application development(design mode or source) is not showing all controls(showing html

Answer 1

What did it for me on a custom control was to first remove the control from my base project. Then I had to pull up the custom control as a separate solution by itself and recompile it. I had to make sure that that it was compiled as a class library and not as a windows application. I had to make sure that it was compiled with Framework 4 (same as my base solution) and that all sub controls and projects were also using framework 4. Once I got all of those things sorted out I went back to my base project and added the newly compiled control and sure enough it was enabled.

I hope this helps someone.