Tried to add a big-mouth clam (ID 7973) with 'Item' Objective Builder and got the following error:

3x ...rfaceFarmingBar\Modules\ObjectiveBuilder.lua:595: attempt to index field 'objective' (a nil value)
...rfaceFarmingBar\Modules\ObjectiveBuilder.lua:595: in function <...rfaceFarmingBar\Modules\ObjectiveBuilder.lua:587>
[C]: ?
...ns\ArkInventory\Externals\Ace3\AceGUI\AceGUI-3.0-41.lua:72: in function <...ns\ArkInventory\Externals\Ace3\AceGUI\AceGUI-3.0.lua:70>
...ns\ArkInventory\Externals\Ace3\AceGUI\AceGUI-3.0-41.lua:306: in function `Fire'
...olic\libs\AceGUI-3.0-41\widgets\AceGUIWidget-Button.lua:22: in function <...olic\libs\AceGUI-3.0\widgets\AceGUIWidget-Button.lua:19>

Client
Classic Wow Phase 5

To Reproduce
Use Objective Builder 'Item' and fill in the information. The error appeared up 'update button'

Expected behavior
Expected item to appear on bar but got errors instead.

No other observations except to attempt again without ArkInventory present.

If you are comfortable trying out a fix, change line 595 in Modules/ObjectiveBuilder.lua to

local oldObjective = button.objective and button.objective.objective

If that doesn't work or you aren't comfortable making that change, I'll look at it tomorrow. Just logged off for the night.

Also if you just want a quick workaround try adding the item from the quick add. I think it's Ctrl shift right click a button to open an editbox to enter an item id. Can't remember off the top of my head.

Ok, I'll give it a go.

Ok, works fine now.