InvalidOperationException: Collection was modified; enumeration operation may not execute.

hi :) I was trying to find why I have freezes when saving the server and accidentally discovered this. I threw out the tree from the main inventory with the right mouse button and clicked the server save bind. Let me clarify that I do not think that the server lags when saving due to this plugin, these are just my observations :) However, if the plugin can affect this, I would appreciate your comments, thank you ;)

 

from console:

InvalidOperationException: Collection was modified; enumeration operation may not execute.

from logs:

InvalidOperationException: Collection was modified; enumeration operation may not execute.
  at System.ThrowHelper.ThrowInvalidOperationException (System.ExceptionResource resource) [0x0000b] in <fb001e01371b4adca20013e0ac763896>:0 
  at System.Collections.Generic.List`1+Enumerator[T].MoveNextRare () [0x00013] in <fb001e01371b4adca20013e0ac763896>:0 
  at System.Collections.Generic.List`1+Enumerator[T].MoveNext () [0x0004a] in <fb001e01371b4adca20013e0ac763896>:0 
  at Oxide.Plugins.Backpacks+BackpackManager+<SaveAllAndKill>d__32.MoveNext () [0x00125] in <5955d707105d4bcf8c25c346b132c23e>:0 
  at UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) [0x00026] in <745c4d442eef4e08b35b5975d62d89d1>:0 

I'll look into it.