Upgraded from 4.2.0 to 4.2.1 and libpurple-based clients were no longer able to connect. After starting the server (cmdline, RedHat Enterprise 6), I got console messages saying
“X11 connection rejected because of wrong authentication.”
I was able to fix this issue by editing the init script to add the option “-Djava.awt.headless=true” to the OPENFIRE_OPTS. Restarting the server fixed it so that libpurple-based clients could connect again. I suspect that the updated JRE needs this option to function on RHEL systems. I think this option should be safe to add to the default init script.
Note that I also saw that libpurple-based clients couldn’t connect after I went to 4.20 as well - the solution there was to disable SSLv2Hello.