Problem exporting after using tempo effect

Hi. I’m using version 2.1.2 on Windows 7 home. I have an hour long stereo track file that I shortened to about 58 1/2 minutes, then added about 20 seconds in an additional track. This was my first time using the tempo effect, I have not used it before. When I tried to export the whole project to .mp3, which I do all the time, the process bogged down with the time-remaining ramping up to hours instead of the 5 minutes or so it usually takes. Any ideas? TIA.

This was a known bug in Audacity 2.1.2 which has been fixed in 2.1.3.
It’s actually just the progress indicator that is broken - if you wait it should complete normally.
To fix the problem, get Audacity 2.1.3 from here: