When Running 5.9.1.0
IT says
Deck not found ! - Brawl Deck

Logs have repeated:
9:47:18 PM:ERROR::ad1f13c9-8723-4202-bb29-4a81dbe290e5 - The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters.
9:55:05 PM:ERROR::ad1f13c9-8723-4202-bb29-4a81dbe290e5 - Unable to cast object of type 'System.String' to type 'System.Byte[]'.


I dont have any brawl quest. And I have my basic settings to Full Autocomplete Quest.
I also have decks made that can complete the quest. And ignore tavern brawl quest is checked.

If I run a specific script in basic settings then it runs fine.