Talking to Sportacus and he has some other kind of a weird crash bug with client atm, so basically, it appears that we'll have to spend some time figuring this stuff out. I'll try to coordinate a client patch during the next data update and hopefully get this stuff repaired. So far I've estabilished that this happens to people who have played/are playing more than 1 server that uses OTclient.
For everyone else, the problem got fixed when deleting that configuration file. Don't know why it doesn't work for you. It appears to be a major problem with OTclient itself. Sorry for this inconvenience.