Blast from the Past Event Week 2 crashing + incomplete quest items

I did Week 2 of the Blast from the Past Event and the game kept crashing multiple times as I progressed through the quests. Unfortunately, just after I completed all the quests for the week and unlocked the reward objects, the game crashed and I could only open my save at a point where my quests hadn't fully finished yet. And now I have three Time Shards in my inventory I can't interact with at all, since the game considers the quests complete and I can't pick up the quest from the crash. Does anyone know of a way to reset my Event progress so I can start Week 2 all over again and get it right?