Since I changed my windows password I can no longer type into a checked out file in Visual Studio 2013! Where before I just needed to start typing and it would check out the
Try: /safemode
I had a similar problem where I could not edit most of my files, but I could edit *.ps1 files.
I don't have TFS, I do have resharper and other plugins.
What worked for me was:
C:\..\IDE>devenv /safemode
That probably has the same effect as suspending and resuming resharper, but I'm not sure which plugin could be causing the problem. If you are having trouble this is something you could try.