WowAce

What version of Grid2 and game type (classic or retail) are you using ?

 latest retail

What game client version (windows or mac) and language are you using ?

 win

What steps will reproduce the problem?

 target a player and try to set focus from tooltip
Did you try having Grid2 as the only enabled addon and everything else disabled?

 yes, without grid2 it is possible

Was it working in a previous version? If yes, which was the last good one?

 i am not sure. 

Do you have an error log of what happened? If you don't see any errors, make sure that error reporting is enabled (`/console scriptErrors 1`) or install [BugSack](https://mods.curse.com/addons/wow/BugSack).

  2x [ADDON_ACTION_FORBIDDEN] AddOn 'Grid2' tried to call the protected function 'FocusUnit()'.
[string "@!BugGrabber\BugGrabber.lua"]:519: in function <!BugGrabber\BugGrabber.lua:519>
[string "=[C]"]: in function `FocusUnit'
[string "@FrameXML\UnitPopup.lua"]:1945: in function `func'
[string "@SharedXML\UIDropDownMenu.lua"]:905: in function `UIDropDownMenuButton_OnClick'
[string "*:OnClick"]:1: in function <[string "*:OnClick"]:1>

Please provide any additional information below.

Working fine here with a player target. Disable the grid2 popupmenu. Uncheck  "General/Appearence/Right Click Menu" option.

It means there won't be resolve or cannot be resolve just because blizzard?

ty

Until some recent patch could not be resolved, try latest version r992-beta.