WowAce

What version of Grid2 are you using?

Grid2-r916-classic 

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

Classic 1.13.2, Windows, Spanish.

What steps will reproduce the problem?

Just click in "raid debuffs"

Did you try having Grid2 as the only enabled addon and everything else disabled?

 Yes

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

Dont remember.

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).

Message: ...e\AddOns\Grid2RaidDebuffsOptions\OptionsAdvanced.lua:134: attempt to index field '?' (a nil value)
Time: Sat Oct 5 03:38:40 2019
Count: 1
Stack: ...e\AddOns\Grid2RaidDebuffsOptions\OptionsAdvanced.lua:134: attempt to index field '?' (a nil value)
...e\AddOns\Grid2RaidDebuffsOptions\OptionsAdvanced.lua:134: in function <...e\AddOns\Grid2RaidDebuffsOptions\OptionsAdvanced.lua:130>
...e\AddOns\Grid2RaidDebuffsOptions\OptionsAdvanced.lua:231: in function <...e\AddOns\Grid2RaidDebuffsOptions\OptionsAdvanced.lua:229>
...e\AddOns\Grid2RaidDebuffsOptions\OptionsAdvanced.lua:275: in function `RefreshAdvancedOptions'
...e\AddOns\Grid2RaidDebuffsOptions\OptionsAdvanced.lua:280: in function `InitAdvancedOptions'
...\Grid2RaidDebuffsOptions\Grid2RaidDebuffsOptions.lua:57: in function `Init'
...\Grid2RaidDebuffsOptions\Grid2RaidDebuffsOptions.lua:6: in function `setupFunc'
Interface\AddOns\Grid2Options\GridStatuses.lua:190: in function `?'
Interface\AddOns\Grid2Options\GridUtils.lua:137: in function `member'
...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:221: in function <...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:169>
(tail call): ?
...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1127: in function <...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1117>
...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1648: in function `FeedGroup'
...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1573: in function <...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0.lua:1557>
[C]: ?
...e\AddOns\Grid2Options\Libs\AceGUI-3.0\AceGUI-3.0.lua:72: in function <...e\AddOns\Grid2Options\Libs\AceGUI-3.0\AceGUI-3.0.lua:70>
...e\AddOns\Grid2Options\Libs\AceGUI-3.0\AceGUI-3.0.lua:287: in function `Fire'
...ibs\AceGUI-3.0\widgets\AceGUIContainer-TreeGroup.lua:515: in function `SetSelected'
...ibs\AceGUI-3.0\widgets\AceGUIContainer-TreeGroup.lua:191: in function <...ibs\AceGUI-3.0\widgets\AceGUIContainer-TreeGroup.lua:187>

Locals: <none>

Please provide any additional information below.

Working fine here, maybe you are using a retail profile with raid debuff modules and settings  that do not exist in classic. If this is the case open grid2 config, and then paste into chat this line:

/script Grid2Options.RDO.db.profile.lastSelectedInstance=nil

Added some code to remove invalid data if a retail raid debuffs config is imported (in r935-beta).

I started over a new profile, with the same configurations and its worked.