This pops up when/while in Edit Mode

2x [ADDON_ACTION_FORBIDDEN] AddOn 'Krowi_AchievementFilter' tried to call the protected function 'ClearTarget()'.
[string "@Interface/AddOns/!BugGrabber/BugGrabber.lua"]:519: in function <Interface/AddOns/!BugGrabber/BugGrabber.lua:519>
[string "=[C]"]: in function ClearTarget' [string "@Interface/FrameXML/EditModeManager.lua"]:1496: in function ResetTargetAndFocus'
[string "@Interface/FrameXML/EditModeManager.lua"]:1479: in function OnEditModeExit' [string "@Interface/FrameXML/EditModeManager.lua"]:185: in function ExitEditMode'
[string "@Interface/FrameXML/EditModeManager.lua"]:205: in function <Interface/FrameXML/EditModeManager.lua:203>
[string "=[C]"]: in function Hide' [string "@Interface/FrameXML/UIParent.lua"]:2828: in function SetUIPanel'
[string "@Interface/FrameXML/UIParent.lua"]:2859: in function MoveUIPanel' [string "@Interface/FrameXML/UIParent.lua"]:2890: in function HideUIPanel'
[string "@Interface/FrameXML/UIParent.lua"]:2556: in function <Interface/FrameXML/UIParent.lua:2548>
[string "=[C]"]: in function SetAttribute' [string "@Interface/FrameXML/UIParent.lua"]:3170: in function HideUIPanel'
[string "@Interface/FrameXML/EditModeManager.lua"]:122: in function `onCloseCallback'
[string "@Interface/SharedXML/SharedUIPanelTemplates.lua"]:127: in function <Interface/SharedXML/SharedUIPanelTemplates.lua:122>

Unfortunately no, logged on toon for the first time of pre-patch, doing Edit Mode in UI and get that error. Does the same for the next few toons.

Are there some steps I can do to reproduce this? Would make it easier for me to check what might be wrong :)

It happens with all addons, it's an issue with the edit mode

This is a Blizzard issue addon devs can't do anything about it. Will be fixed with DF release. See Stanzilla/WoWUIBugs#256 for more information.