Message: wrong number of arguments(1 for 0)
On line 2009 of PokeBattle_Battler is a call to isContactMove? but it passes the wrong number of arguments—I can't remember if it's saying there should be 1 but are 0 or vice-versa, but it should be pretty obvious if you look at that line.
The bug is probably that isContactMove? is defined with a different number of parameters for Breakneck Blitz and all other moves, so I'd recommend Ctrl+Shift-F to search for "def isContactMove?" and compare the definitions.