Validation (): Element ‘<element name>’ "is not supported." Web Custom Control
As Title Only MY CUSTOM WEB CONTROL got this problem, in the source view mode the intellisense are not working, the warning message are Validation (): Element ‘<custom control name>’ "is not supported."  other controls work well. i'm using Visual Studio 2010.
Validation (): Element ‘<element name>’ "is not supported." Web Custom Control
===

As Title Only MY CUSTOM WEB CONTROL got this problem, in the source view mode the intellisense are not working, the warning message are Validation (): Element ‘<custom control name>’ "is not supported."  other controls work well. i'm using Visual Studio 2010.