There was a bug in 0.98.0 (and probably many releases earlier) that would cause the server to crash if a character saved, but left themself connected to the server. The description described seems a little similar to that, and a little different. But it is very hard to try and figure this out just from a description. Even log file output tends not be be very useful - typically, a crash dump with stacktrace is the minimum starting point to figure out the problem. Often, that isn't even enough - further investigation is needed (values of variables and so forth), but some times a stack trace is sufficient to figure the function, and just inspection of the function can sometimes figure it out.