Premiere 2020 & Media encoder failed to export MPEG2
Every time I try to export to MPEG 2 it fails. It always prepares the audio successfully and then immediately fails (both in Premiere and Media Encoder). I recently updated to Premiere Pro 2020 (and in order to do that I was forced to upgrade my iMac's OS to Catalina).
Here is the fail message

I have exported the same type of file with the exact same settings every week for a few years now. This is the first time I've had any trouble.
Here are my settings (I am using a 2015 iMac)



Any ideas?