Server Host Name (FQDN): will not let me change it. I put in my dynamic dns FQDN, and as soon as I tell the screen to save its properties, it changes the field back to my machine name.
Where are you trying to change it? It should be in config/openfire.xml from memory,
The admin console says I should set it:
Server Host Name (FQDN): jardell DNS configuration appears to be missing or incorrect.