I am unable to create Event Handler when i double click on button or anything this messagebox appears

how ever when i add event handler manually it works.any idea what might have i screwed up
thanks
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The class in question is the “MainWindow” class within you
MainWindow.xaml.csfile. Make sure it’s the first class in the code behind file.I suspect you added another type to that file, and defined it at the top. It will “break” the designer, and give you this error message.