From Discord:

I have a new bug that started with version 6.0.0, it's a chain quest called Dawn's Gambit, level 60, from EPL. Every time I log in I get the error: "Questie: [ERROR] Missing event data for Objective: Place Dawn's Gambit id: nil
https://classic.wowhead.com/quest=4771/dawns-gambit

This issue also exists in 6.0.2. Looks like it's been fixed above, but wanted to note just in case. :)

I can confirm this