Hi there!
Probably a compatibility problem between mine and Visustella plugin.
Some Visustella plugin has some plugin parameters that have formulas. I believe maybe there are some formula that is calling the method .param(ID) to return the value of some battler parameter, and that could be the cause of conflict.
The way to go here, is to turn my plugin off and see if the problem persists, if not, then turn my plugin ON and start to turn OFF the visustella plugins listed on the error log, one by one, to find out what is the one causing the compatibility issue.
But as you know, because of the obfuscation, even if we find the one that is conflicting, I may not be able to fix. But will try.