Disconnect when use normal inventoryError

disconnecting: Exception (cs:114033): NullReferenceException: Object reference not set to an instance of an object. ItemDefinition.%05f512bb5437f72c8abe26923ce70c51e886f9a1 (%40ef5e55480a44150f5483c277a71defe6856a9b %b980d182315c39d3bc2fb719df2c982a1da70e6b) (at <00000000000000000000000000000000>:0) SelectedItem.%15693b985bfdabdd8025ddd8ec6bccb256572ed4 (%40ef5e55480a44150f5483c277a71defe6856a9b %b980d182315c39d3bc2fb719df2c982a1da70e6b) (at <00000000000000000000000000000000>:0) SelectedItem.%0cafc5623ae3054ee5311464ac4786d1d12f00de (ItemIcon %eff028c033e3d5a897cc8c9a309e26346108ceaf, System.Boolean %8e3ef37f641501f79e4c06d4d164f133b0af8dd9) (at <00000000000000000000000000000000>:0) ItemIcon.OnPointerClick (UnityEngine.EventSystems.PointerEventData %a675e00478a9fe425921658f2ead092da522b16f) (at <00000000000000000000000000000000>:0) UnityEngine.EventSystems.ExecuteEvents.Execute[T] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.ExecuteEvents+EventFunction`1[T1] functor) (at <00000000000000000000000000000000>:0) UnityEngine.EventSystems.StandaloneInputModule.ReleaseMouse (UnityEngine.EventSystems.PointerEventData pointerEvent, UnityEngine.GameObject currentOverGo) (at <00000000000000000000000000000000>:0) UnityEngine.EventSystems.StandaloneInputModule.ProcessMousePress (UnityEngine.EventSystems.PointerInputModule+MouseButtonEventData data) (at <00000000000000000000000000000000>:0) UnityEngine.EventSystems.StandaloneInputModule.ProcessMouseEvent (System.Int32 id) (at <00000000000000000000000000000000>:0) UnityEngine.EventSystems.StandaloneInputModule.Process () (at <00000000000000000000000000000000>:0) UnityEngine.EventSystems.EventSystem.Update () (at <00000000000000000000000000000000>:0) UnityEngine.EventSystems.EventSystem:Update()

it happens when i open normal inventory with something equiped like knife or guns

What suggests this is caused by the Backpacks plugin?

NKXTQs24ExGTuL8.jpg WhiteThunder

What suggests this is caused by the Backpacks plugin?

there's nothing else related to inventory. If i use /backback so everything is ok if i dont im gonna disconnect.

No problems with either pressing backpack icon, typing /backpack or pressing B (bound key) equipped with any item so far.