Thank you, we tracked it down:
The only thing involving ARI that we have configured by hand is a single entry. We wanted to get the “Swagger” Asterisk page to talk to our server and even though all the guides say it will work if we set “allowed_origins=*”, that command did not seem to function as intended, so we manually named the domain in ari_additional_custom:
But, as it turns out, that conf edit doesn’t take effect until after a reboot I think. It seems like the ARI will crash if we have the conflicting commands both trying to load. The =* wildcard and the =ari.asterisk.org can’t coexist.
Now we removed the ari.asterisk.org entry, rebooted, and the =* now does work when accessing the Asterisk Swagger site. I guess we got mixed up because they needed reboots to take effect, or something.