Visual Studio 2012 detect file changes stopped working

Question

My Visual Studio stopped recognizing external file changes.

I checked the respective options being enabled ('Environment/Documents/Detect when file is changed outside the environment' and 'Environment/Documents/Auto-load changes, if saved).

I restarted Visual Studio as well as my machine.

I tested other software that recognized changes, such as Notepad++, which works just fine.

I tested different Visual Studio projects to check if it has something to do with the project being screwed up somehow - same effect in all projects I tested.

What's going on here?

(There are some SO questions that appear to be related judging by the headline: VS2012 not detecting external changes, Visual Studio 2012 stopped applying changes to solution and Visual Studio 2012 not detecting file change, but all are about different issues.).

Answer 1

Happened to me as well this morning. Exiting VS and relaunching/opening the project seems to have it working again. Super strange!