Ok I've located the problem.

I'm working on server/client environment, cute editor is installed on the server. and my visual studio is on my local,
and I open the cute editor website through my local, and Visual Studio won't recognize the cute editor control and won't even pass the compile.

it's working perfectly when I work on the server directly.

Wondering is there any solutions for the server/client environment, to let my visual studio picking up the cute editor controls and pass the compilation.

Thanks,
Luc