You mean this one?
Message: cannot convert Regexp into Integer
It's a pretty odd problem. Do you know of any changes made prior to it doing that? I'm assuming that wasn't happening all along, so somewhere down the line it must have popped up. Although I'm also going to assume you don't test the battle system every time you make any little changes, since that'd be kind of excessive. So a change was probably made a while in advance of when the error actually popped up on screen, since you wouldn't have known something was wrong without testing the battle system. Was it right after the resolution change?
Message: cannot convert Regexp into Integer
It's a pretty odd problem. Do you know of any changes made prior to it doing that? I'm assuming that wasn't happening all along, so somewhere down the line it must have popped up. Although I'm also going to assume you don't test the battle system every time you make any little changes, since that'd be kind of excessive. So a change was probably made a while in advance of when the error actually popped up on screen, since you wouldn't have known something was wrong without testing the battle system. Was it right after the resolution change?