When I export a file, to save a mp3 file, Audacity freezes. I can’t click the Save or Cancel but everything else on the pop up Save window works. I can’t quit the program either. The program just stuck there, unless reboot the computer. This situation never happened before.
I use MAC ISO Monterey 12.0.1, could someone tell me what I did wrong?
I assume that it is just with this one project. Something worth trying is to copy/paste your track(s) to a new project: For windows, this would be Select:Ctrl+A, Copy:Ctrl+C, File>New, Paste:Ctrl+V. For Mac, I think you use the option key instead of Ctrl. Save the new project. Then exit Audacity and retry your export with the new project.
Thanks. When I export a file, I just click: File → Export → MP3 → Save. Right now, I could easily get to “Save” pop window, but the Save button does not work and the full Audacity is frozen. At the “Save” window, I can make all different choices, but the “Cancel” and “Save” buttons have no reaction. I can’t quit Audacity, the only thing I can do is “View All Windows”, but still can’t save the file or quit Audacity. I have to either reboot the computer or kill the Audacity processor.
I used to export file to MP3 file without any issues. But this problem came up very recently. I have tried a number of times, right now, it freezes every time.
If nobody has this issue, then it must be me did something wrong. But I do not change my saving procedure. I don’t know what is wrong.
I don’t doubt that you are having problems - otherwise you wouldn’t have posted here. 
However, I’m confused. 
Is this a specific issue you are having with one particular project - or does this happen with every project you have including a brand new project ?
We understand that Audacity exports are frozen. Select one of the tracks with the select button on the left. Copy.
Open a fresh Audacity Window and Paste.
Continue until all the tracks are moved.
Did that work? Does the second Audacity window allow you to Export?
Koz