Keep getting this error from time to time and causes the game to massively lag

33x [ADDON_ACTION_BLOCKED] AddOn 'BetterWardrobe' tried to call the protected function 'MountJournal:SetShown()'.
[string "@interface\AddOns!BugGrabber\BugGrabber.lua"]:519: in function <Interface\AddOns!BugGrabber\BugGrabber.lua:519>
[string "=[C]"]: in function SetShown' [string "@Interface\AddOns\Blizzard_Collections\Blizzard_Collections-1.0.lua"]:49: in function <...AddOns\Blizzard_Collections\Blizzard_Collections.lua:41> [string "=[C]"]: in function CollectionsJournal_UpdateSelectedTab'
[string "@interface\AddOns\Blizzard_Collections\Blizzard_Collections-1.0.lua"]:6: in function CollectionsJournal_SetTab' [string "@Interface\AddOns\BetterWardrobe\Modules\Wardrobe-Appearances.lua"]:1786: in function CheckLatestAppearance'
[string "@interface\AddOns\BetterWardrobe\Modules\Wardrobe-Appearances.lua"]:1768: in function <Interface\AddOns\BetterWardrobe\Modules\Wardrobe.lua:1751>

Adding on my errors with Better Wardrobe as well.

This first one looks like taint, who knows from where.
5x [ADDON_ACTION_FORBIDDEN] AddOn 'BetterWardrobe' tried to call the protected function 'UNKNOWN()'. [string "@!BugGrabber/BugGrabber.lua"]:480: in function <!BugGrabber/BugGrabber.lua:480> [string "=[C]"]: ? [string "=[C]"]: ? [string "=[C]"]: in function UseContainerItem'
[string "@FrameXML/ContainerFrame.lua"]:1402: in function <FrameXML/ContainerFrame.lua:1311>
[string "=[C]"]: in function ContainerFrameItemButton_OnClick' [string "@FrameXML/ContainerFrame.lua"]:1454: in function <FrameXML/ContainerFrame.lua:1441>

This second one looks more in-line with what OP is getting.
21x [ADDON_ACTION_BLOCKED] AddOn 'BetterWardrobe' tried to call the protected function 'MountJournal:SetShown()'. [string "@!BugGrabber/BugGrabber.lua"]:480: in function <!BugGrabber/BugGrabber.lua:480> [string "=[C]"]: in function SetShown'
[string "@Blizzard_Collections/Blizzard_Collections.lua"]:62: in function <Blizzard_Collections/Blizzard_Collections.lua:54>
[string "=[C]"]: in function CollectionsJournal_UpdateSelectedTab' [string "@Blizzard_Collections/Blizzard_Collections.lua"]:6: in function CollectionsJournal_SetTab'
[string "@BetterWardrobe/Modules/Wardrobe.lua"]:1817: in function CheckLatestAppearance' [string "@BetterWardrobe/Modules/Wardrobe.lua"]:1799: in function <BetterWardrobe/Modules/Wardrobe.lua:1782>