OLM.NET fixed this pretty fast, and it was a problem on their end.
The problem was related to the sticky bit permissions on the /tmp directory. I don’t have any real privs on the box, so I’m not sure exactly what the case was.
Suffice to say, it was permissions related on the /tmp directory, as the error code and faq indicated.
The permissions must have changed literally today, because it was working fine last night.
Thanks.