Most of the time, even with a "fresh" install and database, on server start a message is printed to the terminal as follows:

PMGD Response:
{
   "info" : "ReadOnly: ",
   "status" : -1
}

[
   {
      "FailedCommand" : "Transaction",
      "info" : "Failed PMGD Transaction: ReadOnly: ",
      "status" : -1
   }
]

This is mildly confusing, given the server otherwise appears to function as expected, with clients able to connect and interact.

This error arises due to the auto_delete query that runs as the server launches. A fresh database has no data/metadata so the query necessarily hiccups. While this is technically valid behavior it is confusing from an operator/client perspective.