Getting a 503 error after upgrading to 5.0.3 when trying to access the admin site

I recently upgraded Openfire Server from 4.8.1 to 5.0.3. Since then, I cannot access the admin side whether it is on the network or from the host server itself. I have gone to the openfire.xml file and verified that the line 127.0.0.1 is deleted. Here is a screenshot of the error I get:

Spark is still working on every machine on the network, I just can’t access the admin side.

Any help is greatly appreciated! I am new to working on servers and new to Openfire. Thanks!

Same issue. Had to roll back to older version of Openfire. Anyone?

Could you maybe check the logs at startup? if you’re on linux, it should be under /usr/share/openfire/logs/
See if there’s any error concerning the admin page?

This does not ring a bell with me either. As @iro wrote, it would be very helpful to know what Openfire logs at startup. Have a look at the logfiles, but also the console output and things like syslog.