It doesn't give me any sort of error message or prohibit me, but when I check the location, there's nothing saved there, or any indication that anything has saved. When I search the mac for the file I tried to create, it doesn't exist
Edit: I will try to save to the downloads directory, I'll let you know how it goes
Yeah, finding the downloads directory on a mac isn't obvious. Sorry, my fault. Let's try something simpler.
I know you said you tried downloading to different places, so just some quick troubleshooting.
1) Open any directory you want to save the file to. (e.g. in your screenshot, choose 'home')
2) With that directory open, save your mod file to that location
3) You should see the file pop up in that location once it gets saved
If this works, move the file to the mods folder manually. My guess is there was an error in your original 'save to' path.
If this doesn't work, my first guess is that this might be a Mac specific issue.