[Error] Battles crash game to desktop now - why?

[SuperSpyroDragon64]

[Pokémon Essentials version 19.1]
[Generation 8 Project v1.1.0]
[v19.1 Hotfixes 1.0.7]

Exception: RuntimeError
Message: Script error in event 40 (coords 1,1), map 4 (Pokémon Lab):
Exception: NoMethodError
Message: undefined method `>' for nil:NilClass

***Full script:
pbTrainerBattle(:LEADER_Brock, "Brock")

Backtrace:
176:Battle_Action_Switching:364:in `pbOnActiveOne'
154:Battler_AbilityAndItem:7:in `pbEffectsOnSwitchIn'
176:Battle_Action_Switching:312:in `block in pbOnActiveAll'
176:Battle_Action_Switching:312:in `each'
176:Battle_Action_Switching:312:in `pbOnActiveAll'
173:Battle_StartAndEnd:301:in `pbStartBattleCore'
173:Battle_StartAndEnd:258:in `pbStartBattle'
230:Overworld_BattleStarting:442:in `block (2 levels) in pbTrainerBattleCore'
231:Overworld_BattleIntroAnim:8:in `pbSceneStandby'
230:Overworld_BattleStarting:441:in `block in pbTrainerBattleCore'


Backtrace:
033:Interpreter:189:in `rescue in execute_script'
033:Interpreter:135:in `execute_script'
034:Interpreter_Commands:352:in `command_111'
034:Interpreter_Commands:29:in `execute_command'
033:Interpreter:127:in `block in update'
033:Interpreter:87:in `loop'
033:Interpreter:87:in `update'
032:Scene_Map:157:in `block in update'
032:Scene_Map:155:in `loop'
032:Scene_Map:155:in `update'