If one (MVC4 Cool Towel SPA) VS is in debug mode and you open also in VS of a former version with the same solution name for some copy and paste work, if EF has changed, stop debug, start debug, newest version is all of the sudden out of sync with EF, maybe the corruption happens here, moreover closing the former version VS, does not fix the problem, you must reboot the computer, and then you discover that your newest version solution SPA has all kinds of weird errors typical for corruption.
Could you please fix this? Its a consequence that you do not want the VS GUI be cluttered with "Save solution (with all files) as ...", in name for all people that do not have source control!