For some bizarre reason, when checking out a file in TFS, your project gets recompiled. This is annoying if you’re in the middle of working on your web application while you do the checkout.
Thank you to this StackOverflow answer for the details:
Navigate to C:\Users[user]\AppData\Roaming\Microsoft\VisualStudio\11.0\
Delete the app_offline.htm file
Create a directory called app_offline.htm
Visual Studio apparently gets confused and doesn’t know how to screw up your work anymore.