Force Quit Audacity.
Open Finder, choose Go > Go to Folder and type:
~/Library/Application Support/audacity/
Open the audacity.cfg file in TextEdit and look for the line that says [Directories]. Underneath that line, look what it says for “TempDir”.
Use Go to Folder to open that TempDir location.
Look for a folder called audacity-, for example if your user name on the computer is doaler, look for the audacity-doaler folder. Delete that folder.
That should solve the problem.
Gale