Chris, I just committed a fix that should at least prevent the crash, but I couldn't figure out why the underlying problem (it either not finding anything in this.LocalPlayer.UnlockedBonusShipTypes around line 974 for TutorialStep.cs, or finding one that doesn't exist in ShipTypeData.Dictionary ) was happening, or really how it could happen.
Anyway, you should probably take a look to make sure what I did won't make it worse.