Broken links instead of new passages

Hi,

I'm working on a rather long story in Twine 2.1.2 Harlowe 2.0.1.

For some reason, when I'm creating a new link like typing in [[example]] Twine no longer creates a new passage on its own. Only a broken link with a red x at the end appears. So I have to click on "+Passage" and name the new passage myself, which is rather time-consuming...
Help, please?