I'm having a problem. I've gotten every research thing done with mods and it goes to the mc main menu, but when I join the world it crashes due to the GUI research menu. I've tried configuring the x and y, but it still crashes no matter what. Could anyone help me.

java.lang.NullPointerException: Ticking player
at vault_research.research.ResearchTree.restrictedBy(ResearchTree.java:143) ~[?:1.0.0] {re:classloading}
at vault_research.research.StageManager.onItemEquip(StageManager.java:153) ~[?:1.0.0] {re:classloading}
at net.minecraftforge.eventbus.ASMEventHandler_1864_StageManager_onItemEquip_LivingEquipmentChangeEvent.invoke(.dynamic) ~[?:?] {}
at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:85) ~[eventbus-4.0.0.jar:?] {}
at net.minecraftforge.eventbus.EventBus$$Lambda$3475/691171870.invoke(Unknown Source) ~[?:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-4.0.0.jar:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-4.0.0.jar:?] {}