Sometimes MUSHclient will crash. When I restart MUSHclient I'll try to setup to receive chat calls again but can't because the previous instance of MUSHclient was receiving calls on that same port # and the crash didn't release the port.
Cannot accept calls on port 4050, code = 10048 (Address already in use)
Is there anyway to free that port in Windows XP?
Probably MUSHclient is still in memory somewhere. I'm pretty sure that all modern OSes release any system resources held by a crashed program - including opened ports.
Take a look in your taskmanager?
In some rare instances, it takes a little bit for the OS to clean everything up. Usually it happens when the process is destroyed or a few seconds thereafter, but very occasionally I've seen it take almost a minute. That could be what the OP is seeing here.
But I'd definitely start with what Worstje suggested and make sure that it's not actually still around.
Thanks for the tip, MUSHclient is listed once in taskmanager, appears to be the process of MUSHclient that was created after I relaunched it.