Not 100% sure if the only fault was related to this, but no additional error was shown, the entire client nearly crashed a few times during raiding.

• Addon version: 10.0.16
• Server patch: 10.0.5
  3x [ADDON_ACTION_BLOCKED] AddOn 'Bagnon' tried to call the protected function 'MultiBarBottomLeftButton5:SetAttribute()'.
  [string "@!BugGrabber/BugGrabber.lua"]:480: in function <!BugGrabber/BugGrabber.lua:480>
  [string "=[C]"]: in function SetAttribute' [string "@FrameXML/ActionButton.lua"]:350: in function UpdatePressAndHoldAction'
  [string "@FrameXML/ActionButton.lua"]:412: in function Update' [string "@FrameXML/ActionButton.lua"]:362: in function UpdateAction'
  [string "@FrameXML/ActionButton.lua"]:821: in function `OnEvent'
  [string "@FrameXML/ActionButton.lua"]:216: in function <FrameXML/ActionButton.lua:213>