When I rebooted the server recently to patch some linux kernel vulnerabilities it messed up Prosody and was unable to read the certificate files because of a bash script I made to copy over the Let’s Encrypt certificates in a cronjob. I did chmod 600 instead of 700 in the script so it made the files unreadable to Prosody. WOW was that a dumb mistake… Sorry about that! Good thing it was only about 20 minutes of downtime. Took me a while to figure it out while I was tired. (Note to self, don’t reboot server when tired).
Here is the script if you were curious.