Show suppressed errors not working

I am examining the Visual Studio 2010 Architectural Tools. I created a Layer Diagram and created 3 Layers (UI - BIZ - DAL), i attached some classes to layers and generated dependencies. After i validated 开发者_如何学Carchitecture i saw errors. Then, i right-click an error and select Suppress Error, so the error disappeared.

Now, i can't bring back the error. I click "Show Suppressed Errors"; but nothing happens.

What is wrong?

I found the way how i bring the errors back. When you suppress an error, a file is generated by VS that name is DiagramName.diagramtype.suppress. You can delete any suppress that you want.

After that, you error come back :)