After installing FPBX17 on D12 I get a message on console saying.
1 updates could not be installed automatically.
see /var/log/unattended-upgrades/unattended-upgrades.log
after unattended-upgrades runs the first time on the daily timer/cron. On a new install you can run that command manually to see the message immediately
There is nothing in that log file indicating any problem. After doing an internet search for similar problems I determined that this shows up after unattended-upgrades runs which then creates /var/lib/unattended-upgrades/kept-back. Inside that file is line item ffmpeg. Deleting that kept-back file or removing the line item inside it only removes the erroneous message until the next time unattended-upgrades runs. apt install ffmpeg says ffmpeg is already the newest version (5.1.4-8.sng12).
apt purge ffmpeg gets rid of the erroneous message. apt install ffmpeg brings it back. Commenting out the freepbx repo and installing the newer ffmpeg version from official debian repo also gets rid of the error, so I guess it’s because of that newer upstream version. So far I haven’t found any way to have it ignore that higher upstream version and suppress the erroneous error.