When trying to equip a carriable items, an exception is thrown:

200705T155908.217 [EXCEPTION] [System.ThrowHelper.ThrowArgumentOutOfRangeException] ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
   at System.ThrowHelper.ThrowArgumentOutOfRangeException (System.ExceptionArgument argument, System.ExceptionResource resource) (at <ad04dee02e7e4a85a1299c7ee81c79f6>:0)
   at System.ThrowHelper.ThrowArgumentOutOfRangeException () (at <ad04dee02e7e4a85a1299c7ee81c79f6>:0)
   at ProtoPartSnapshot.Load (Vessel vesselRef, System.Boolean loadAsRootPart) (at <c168e21ec56346b082f89043e76162e1>:0)
   at KIS.KIS_Shared.CreatePart (ConfigNode partConfig, UnityEngine.Vector3 position, UnityEngine.Quaternion rotation, Part fromPart, Part coupleToPart, System.String srcAttachNodeId, AttachNode tgtAttachNode, KIS.KIS_Shared+OnPartReady onPartReady, System.Boolean createPhysicsless) (at <260264fece7f4aefbe53a4372aaba441>:0)
   at KIS.KISAddonPickup.CreateDrop (Part tgtPart, UnityEngine.Vector3 pos, UnityEngine.Quaternion rot) (at <260264fece7f4aefbe53a4372aaba441>:0)
   at KIS.KISAddonPickup.OnPointerAction (KIS.KISAddonPointer+PointerTarget pointerTarget, UnityEngine.Vector3 pos, UnityEngine.Quaternion rot, Part tgtPart, System.String srcAttachNodeID, AttachNode tgtAttachNode) (at <260264fece7f4aefbe53a4372aaba441>:0)
   at KIS.KISAddonPointer.UpdatePointer () (at <260264fece7f4aefbe53a4372aaba441>:0)
   at KIS.KISAddonPointer.Update () (at <260264fece7f4aefbe53a4372aaba441>:0)
   at UnityEngine.DebugLogHandler:LogException(Exception, Object)
   at ModuleManager.UnityLogHandle.InterceptLogHandler:LogException(Exception, Object)
   at UnityEngine.Debug:CallOverridenDebugHandler(Exception, Object)

Hello,

I think I have the same trouble. I get it with Extraplanetary Launchpads Survey Stake.
I get it when I want to attach the yurvey to the ground. It is decrease in the inventory but not attached.

Here is my log, the exception seems the same as yours

[LOG 00:42:27.197] [Part:kerbalEVAfemale (Ditorinne Kerman) (id=F116547109)#Module:14] End item pickup: item=KS-BBQ Survey Stake, fromPart=[Part:kerbalEVAfemale (Ditorinne Kerman) (id=F116547109)]
[LOG 00:42:27.208] KIS UI lock acquired
[LOG 00:42:27.209] Set pointer mode to: Drop
[LOG 00:42:28.216] Set pointer mode to: Attach
[LOG 00:42:30.079] Create part & attach: tgtPart=[NULL]
[EXC 00:42:30.082] ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
System.ThrowHelper.ThrowArgumentOutOfRangeException (System.ExceptionArgument argument, System.ExceptionResource resource) (at :0)
System.ThrowHelper.ThrowArgumentOutOfRangeException () (at :0)
ProtoPartSnapshot.Load (Vessel vesselRef, System.Boolean loadAsRootPart) (at :0)
KIS.KIS_Shared.CreatePart (ConfigNode partConfig, UnityEngine.Vector3 position, UnityEngine.Quaternion rotation, Part fromPart, Part coupleToPart, System.String srcAttachNodeId, AttachNode tgtAttachNode, KIS.KIS_Shared+OnPartReady onPartReady, System.Boolean createPhysicsless) (at <260264fece7f4aefbe53a4372aaba441>:0)
KIS.KISAddonPickup.CreateAttach (Part tgtPart, UnityEngine.Vector3 pos, UnityEngine.Quaternion rot, System.String srcAttachNodeID, AttachNode tgtAttachNode) (at <260264fece7f4aefbe53a4372aaba441>:0)
KIS.KISAddonPickup.OnPointerAction (KIS.KISAddonPointer+PointerTarget pointerTarget, UnityEngine.Vector3 pos, UnityEngine.Quaternion rot, Part tgtPart, System.String srcAttachNodeID, AttachNode tgtAttachNode) (at <260264fece7f4aefbe53a4372aaba441>:0)
KIS.KISAddonPointer.UpdatePointer () (at <260264fece7f4aefbe53a4372aaba441>:0)
KIS.KISAddonPointer.Update () (at <260264fece7f4aefbe53a4372aaba441>:0)
UnityEngine.DebugLogHandler:LogException(Exception, Object)
ModuleManager.UnityLogHandle.InterceptLogHandler:LogException(Exception, Object)
UnityEngine.Debug:CallOverridenDebugHandler(Exception, Object)
[LOG 00:42:33.311] Set pointer mode to: Drop
[LOG 00:42:34.448] Set pointer mode to: Nothing
[LOG 00:42:34.485] KIS UI lock released