Got this error when I went to use a quest item - the milk in a skull cup if that matters for the BfA quest. Asked me to disable the addon, but a reloadui fixed the issue.

1x [ADDON_ACTION_FORBIDDEN] AddOn 'Prat-3.0-3.9.36' tried to call the protected function 'UNKNOWN()'.
[string "@!BugGrabber/BugGrabber.lua"]:481: in function <!BugGrabber/BugGrabber.lua:481>
[string "=[C]"]: ?
[string "=[C]"]: ?
[string "=[C]"]: ?
[string "=[C]"]: ?
[string "=[C]"]: in function UseContainerItem' [string "@FrameXML/ContainerFrame.lua"]:1424: in function <FrameXML/ContainerFrame.lua:1333> [string "=[C]"]: in function ContainerFrameItemButton_OnClick'
[string "@FrameXML/ContainerFrame.lua"]:1476: in function <FrameXML/ContainerFrame.lua:1463>

Locals:
_ = Frame {
RegisterEvent = defined @!BugGrabber/BugGrabber.lua:487
0 =
UnregisterEvent = defined @!BugGrabber/BugGrabber.lua:487
SetScript = defined @!BugGrabber/BugGrabber.lua:487
}
event = "ADDON_ACTION_FORBIDDEN"
events =

This kind of error is difficult to fix. To acquire the information needed to fix the issue turn on the taint log with

/console taintLog 1

play WoW until the error happens, and when it does close WoW and submit the contents of this file:

[Your WoW Directory]/_retail_/Logs/taint.log