Audacity stopped recordimg

I was going along just fine when I stopped, backed up a little to re-do a sentence … and then, voila, I could not get it to record again. I even killed the recording and thought I’d just start anew … but alas and alack, it still won’t record. How have I screwed this up???

There’s something like a red map pin that I haven’t noticed before and I can’t get past it … is this the problem and, if so, now what?

The “red map pin” is normally (by default) a “red triangle” during recording, and a “green triangle” on playback.
To get the normal “triangle” rather than “map pin”, just click on it. (This does not solve the problem of not recording)
See here for details about the map in / triangle:

What were you recording? (Example: Your voice with a Samson C01 USB microphone.)