Bug #5183249178249102741982471982743189 - see title:

1x [ADDON_ACTION_BLOCKED] AddOn 'Bagnon' tried to call the protected function 'UNKNOWN()'.
[string "@!BugGrabber/BugGrabber.lua"]:480: in function <!BugGrabber/BugGrabber.lua:480>
[string "=[C]"]: ?
[string "=[C]"]: in function PickupContainerItem' [string "@FrameXML/ContainerFrame.lua"]:1335: in function <FrameXML/ContainerFrame.lua:1312> [string "=[C]"]: in function ContainerFrameItemButton_OnClick'
[string "@FrameXML/ContainerFrame.lua"]:1455: in function OnClick' [string "@FrameXML/ContainerFrame.lua"]:1571: in function OnDragStart'
[string "@FrameXML/ContainerFrame.lua"]:1575: in function <FrameXML/ContainerFrame.lua:1574>

Locals:
_ = Frame {
RegisterEvent = defined @!BugGrabber/BugGrabber.lua:486
0 =
UnregisterEvent = defined @!BugGrabber/BugGrabber.lua:486
SetScript = defined @!BugGrabber/BugGrabber.lua:486
}
event = "ADDON_ACTION_BLOCKED"
events =

{
ADDON_ACTION_BLOCKED = defined @!BugGrabber/BugGrabber.lua:552
ADDON_ACTION_FORBIDDEN = defined @!BugGrabber/BugGrabber.lua:552
PLAYER_LOGIN = defined @!BugGrabber/BugGrabber.lua:546
LUA_WARNING = defined @!BugGrabber/BugGrabber.lua:561
ADDON_LOADED = defined @!BugGrabber/BugGrabber.lua:506
}

Update - this bug only happens when moving items around in PRIMARY small blizzard bag. All other bags they can be moved fine.