Thanks for your report. This shows that value of tilex and tiley can go way out of range due to some bug. If you are able to reproduce this issue it would be very helpful to put some info about it here. Currently I have no idea how to reproduce this.

Because this is not the first time I see a user with this issue and the reason for this bug still remains unknown I will simply remove the bug outcome in next release. I will limit those values to valid range during config file load so next time it will be enough to restart the app after this bug occurs.