A few months ago for some unknown reason the Output pane in Visual Studio stopped displaying output from my application.

I’d get the build notices, exceptions, and thread/process exit information but any calls to Debug or Console to output information wouldn’t display.

It turns out that you can de-select “Program Output” – and somehow it’d become deselected. Even now it still turns itself off, apparently by random.

Right clicking in the Output pane should let you re-select that value.