is
Jon Skeet
Visual Studio 2012 does not show folder has been created
I use Microsoft Visual Studio 2012. I first opened my ASP.NET project, then I created some folder as Pages, Views, Sources. But the second I open the project, Visual Studio doesn't show those folders. I cannot view them. If I make a new folder with the same name above, the IDE renders a message that the folder already exists.
Can you help me! Thank you very much!
Yes, this is because Visual Studio needs all its resources explicitly listed in its project files. When you add a folder in VS, it creates it on disk and changes the project file - whereas if you've added it in Explorer, the project file won't have any information about it.
The simplest solution I find is usually to rename them in explorer, add them in Visual Studio, then move the content from the original folder into the new one.
Alternatively, you could edit the project files directly, but that's slightly more advanced and dangerous. (It's not really that hard, and probably worth experimenting with if you've committed the "known good" project file.)
See more on this question at Stackoverflow