That is odd, the config should not cause a error in clicking start
Can confirm this is happening for me. For context, I ran the macro the morning after being on in the GL all night. It will set up the Common Conversion, but won't start it. Just hangs and eventually the macro "times out" and ends. In the case this morning, even when I watched over the macro and started all the quests manually, one of the agents blocked it from starting (failed to start, verify your agents...). Restarting the macro yields the same behavior. But the macro only "worked" if I directly selected Yes on dialog. The code in error is the same as reported by Sum1 above.
[10/26/2020 08:00:31] [<character name>] v. \at1.29\ax Configuration: \atOverseer_<character name>.ini\ax
[10/26/2020 08:00:31] [<character name>] Starting Cycle (08:00:31)
[10/26/2020 08:00:31] [<character name>] Collecting any pending rewards
[10/26/2020 08:00:31] [<character name>] No more rewards to claim
[10/26/2020 08:00:31] [<character name>] Claiming Completed Missions
[10/26/2020 08:00:31] [<character name>] No active quests
[10/26/2020 08:00:31] [<character name>] Collecting any pending rewards
[10/26/2020 08:00:32] [<character name>] No more rewards to claim
[10/26/2020 08:00:32] [<character name>] Checking all conversion quests
[10/26/2020 08:00:40] [<character name>] .....Starting quest Common Conversion with 100% success.
[10/26/2020 08:00:51] [<character name>] **ERROR: FAILED START. Attempting quest again with different agents.
[10/26/2020 08:00:52] [<character name>] Ignoring minions:
[10/26/2020 08:00:52] [<character name>] * Dealer
[10/26/2020 08:00:52] [<character name>] * Emissary
[10/26/2020 08:00:52] [<character name>] * Acolyte
[10/26/2020 08:00:54] [<character name>] ...ignoring excluded agent Dealer
[10/26/2020 08:00:54] [<character name>] ...ignoring excluded agent Emissary
[10/26/2020 08:00:54] [<character name>] ...ignoring excluded agent Acolyte
[10/26/2020 08:00:55] [<character name>] ...ignoring excluded agent Dealer
[10/26/2020 08:00:55] [<character name>] ...ignoring excluded agent Emissary
[10/26/2020 08:00:55] [<character name>] ...ignoring excluded agent Acolyte
[10/26/2020 08:00:56] [<character name>] ...ignoring excluded agent Dealer
[10/26/2020 08:00:56] [<character name>] ...ignoring excluded agent Emissary
[10/26/2020 08:00:56] [<character name>] ...ignoring excluded agent Acolyte
[10/26/2020 08:00:57] [<character name>] .....Starting quest Common Conversion with 100% success.
[10/26/2020 08:01:10] [<character name>] Waiting for quest to complete: Common
[10/26/2020 08:01:13] [<character name>] Common Conversion has succeeded. Claiming.
[10/26/2020 08:01:15] [<character name>] ...ignoring excluded agent Dealer
[10/26/2020 08:01:18] [<character name>] .....Starting quest Common Conversion with 100% success.
[10/26/2020 08:01:29] [<character name>] Common Conversion not found.
[10/26/2020 08:01:29] [<character name>] ERROR