Turning off the new “Enable Edit and Continue” feature fixed it for me.
- Open Options dialog box (Tools | Options)
- Locate “Debugging\Edit and Continue”
- Uncheck “Enable Edit and Continue”
Update 1:
You can also turn it off on a per project basis.
- Open properties for web project
- Select Web tab
- Uncheck “Enable Edit and Continue” in the “Debuggers” section
Update 2:
Blog article that discusses this feature.