While using Visual Studio I occasionally experience odd input 'quirks.' Certain types of input don't get through to the editor, while others do. It seems linked to one of the modifier keys (Ctrl, Alt, Shift) becoming 'locked' and causing the input to get routed in an alternate manner.
It occurs, almost exclusively, while I'm editing a WPF control's XAML. There are always multiple VS workspaces open across multiple monitors, but I'm not sure if that is linked to the issue, since that is a near-constant attribute of my development.
When the issue occurs, I can sometimes change window focus, save-all open files, and/or minimize all VS windows to resolve; although occasionally none of these work and I must completely restart VS.
I've turned Windows Sticky Keys off (although I was sure I wasn't toggling them), but that did not resolve the issue.
Similar question: Visual Studio 2010: Editor stops responding to keyboard