I saw some comments about the game crashing when Syle confronts the first Fairy during the Aura Breaks class and I think I know why what it happens. In RPG Maker MV, the game keeps track of what images are used for the Face, Character, and [SV] Battler for the Actors which can be changed through the Change Actor Images command. When a new game is started, it loads the images as defined in the Actors database (data/Actors.json) to use as a default which it will also default to when Initialize is checked in the Change Party Member command. The purpose of this behavior is so the game keeps the images used for that actor for instances where the character may use a different graphic other than the default such as school/academy or wedding so that loading the game will use that graphic rather than default images.
I guess when you worked on 0.6, Uni was set to use Actor2_6.png (I guess it was a placeholder until Uni's graphic was done) which wouldn't be a problem since the player was only meant to use Syle, Ein, and Alyssa as well as Jin for one battle. However, 0.7 had Uni use a different graphic which Lawmage Academy should use but the problem is that 0.6 had her still use Actor2_6.png as the SV Battler so when you confront the Fairy, the game displays a Loading Error since Lawmage Academy is looking for Actor2_6.png. That's why starting a new game in 0.7 doesn't cause this error since Uni will use her proper graphic.
I tested this behavior by editing Actor 4 (who I named also Alyssa) of my project to use Alyssa.png as the Character, starting a new game and saving, changing Actor 4's Character back to the original, and removing the Alyssa.png file. By loading the save I made earlier, the game generated an error when I added Actor 4 which I could click Retry until the game crashed when I changed maps. If I Initialized Actor 4 (Alyssa) instead (or changed her graphics through the Change Actor Images before adding her), she would use graphic defined in the database thus the error doesn't occur.