Playback mode won't stop

I’m editing an unusually long track. About an hour long. Maybe that’s why this is happening. The last time I hit my spacebar to continue looking for a glitch to edit out it just kept rolling along. No sound is outputting. I’ve hit every key, every option there is and that little sucker just keeps rolling along like Ol’ Man River. It’s been going along for about ten minutes now. I guess it’s got another ten before it reaches the end. I don’t want to exit and lose about an hour’s worth of editing.

There is one other person asking about this, but I can’t see where it was answered. I’ll probably have figured this out before y’all can get to this, but might as well get it answered for the next poor sucker this happens to.

First thing I’ll do is cut it into two or three separate tracks. So, if Ol’ Man River wants to shanghai me again, at least it won’t be such a slow boat to China.

Spacebar should toggle play / stop.
Clicking the “Stop” button should also stop playback

Which version of Audacity do you have?
Is the “Scrub Ruler” visible?

I just had the exact same problem with Audacity 2.4.2 in OSX 10.11 - suddenly playing without sound and nothing would stop it. All menus were greyed out. Play and stop buttons were highlighted, so it looks like both were stuck on. I don’t use the buttons, so I suspect I butterfingered some shortcut key combination that set that off. I had to wait for it to play to the end of the track. Only other option was to tell OSX to force quit it.

I’ll report this as a but in the OSX forum.