Files saved from Quicktime with Export Audio Only can't be opened (error message)
Because there doesn't seem to be a way to record just sound from a website without downloading other stuff and doing something fancy, I'm using QuickTime to do a screen recording, and then using Export Audio Only to get an M4A with just the sound. I've done this before with no difficulty, but now when I create and try to open a file of this type, whether with QuickTime, iTunes, or even VLC which normally opens EVERYTHING, I get an error message:
"az.m4a" can't be opened because it is from an unidentified developer
To make this even crazier, I exported a SECOND audio file from the same video screen capture, and the first time I clicked on it, it opened and played fine in iTunes, I deleted it from there, changed it to opening automatically in QuickTime, it opened and played fine again, so I assumed that there'd just been some sort of error in creating the first audio file… But when I went back later and tried to open the new file that had previously worked fine, it gave the SAME error message!
Nothing has been added, changed, or deleted from the system on my desktop since the last time I did this with no problems. The computer has been restarted to no avail. Does anyone have any ideas on what the heck is going on here? Thanks!
Mojave 10.14.6
QuickTime 10.5
iMac 27″, macOS 10.14