When upgrading Openfire 4.2.3 to Openfire 4.3.0-beta (on Windows), after the upgrade the folder plugins/admin/webapp/WEB-INF/lib is left in place - this prevents various pages on the admin console from starting.
Maybe it only happens if 32-bit version was used in the past. But my last upgrade was x64 to x64. Lib folder is not removed during the upgrade. As this is a rare case, it can probably be changed to Major.
I was unable to reproduce this issue. My test was simple.
default installation, no additional plug-ins.
same arch 4.0.0 to 4.1.0 to 4.2.3 to 4.3.0 - no issues
32 bit 4.1.0 to 64bit 4.2.3 to 64bit 4.3.0 - no issues
is the issue that the admin console can not be accessed at all, or just certain pages within the admin console
In my case i couldn't access main page and TLS/SSL. But by manually specifying URL i could go to other pages.