I had the same thing happen a few days ago. It quit doing that and started letting that charachter log in, but immediately log out again, leaving that account unable to log in at all until the affected charachter finally times oit. (oh yeah, forgot to mention that after i started getting pasat that message, onlyone charachter remained affected, the oithers on that account seem fine.
There was an apparent reboot, and after that everything was fine again, then it all happened again. same character affected, but could be coimcidence as i was playing that same charachter again when it crashed on me again too.)
Anyway, its happening same way on two computers, one win10 other win11, so its not an individual computer problem, its apparently either account or charachter slot related. not on the computer, cant fix on the computer. apprently reboot of server4 fixes, but we chant be having constant reboots, so kind of just one of those things for now I guess.
Found a post from August 2020 with the same symptoms. Parsnip replied with some questions and after those were answered there seems no more conversation and that was apparently the only thread by that charachter.
Parsnips questions then:
Hmm odd that your other accounts work but can we first run through a few basics:
1) Did you install with the UOF Launcher?
2) Are you art files fully up to date?
3) What client are you using (ClassicUO or old client)?
My own answers.
1) Yes installed UOF Launcher from UOF webpage in last month on my return to UO Forever,
2) Unless I;m missing something since less than a month ago. I will note that when I load it directly, it will say its loading 2 files, load them, and if I log in still get the same reults, and same two files are reloading next time. Oddly only one charachter slot will not play.
3) ummmm... loaded last month so ClassicUO. Wish I had the old computer from theoriginal load 6 months after server opened to test with, but it refused to be a jab and died from the Blue Screen variant.