Fix "Could not find file AppManifest.xaml" issue

习惯了英文来写，还是用英文了。

 

I got an issue when I build my silverlight project. I got  an error "Could not find file AppManifest.xaml".

I tried to figure it out as follows:

1. Clean solution

2. Go to "Obj" folder, delete error files

3. Rebuild it

Fix it.