I’m a newbie and need help. I have about 20 one-hour files from which I want to select about 20 tracks for a master disc. I was able to load and select a segment, but I was warned I did not have enough disk space (I have 1.37 Tb available). I am using 2.11 on Mac 10.10.5. I now cannot repeat that select and export step.
The first issue might be the version. There is no 2.11.
How many files did you open at the same time? All of them? Audacity might be complaining about hardware memory, not hard disk space. How much RAM have you got?
Apple > About This Mac > Memory.
But you should deal with the version first.
Make sure you have Audacity 2.1.1 from http://audacityteam.org/download/mac and install it according to these instructions: https://forum.audacityteam.org/t/installation-do-not-run-audacity-from-the-dmg/31711/1
Have you tried changing the location you are trying to export to?