PC's can't level up/use Charactermancer

They have been able to level up before, but now it doesnt work. They are able to launch the level up screen, but it's missing things, not able to roll HP, and one guy had (undefined) as the only thing added. I have tried to make a copy and it didnt work.  I'm using the base 5e and Curse of Strahd template, but I have often tried messing with the settings to change things. Anyone have any ideas?

If you create a new Character Sheet and use the character mancer on this, does it work or not? IF Leveling Up works on the new character, then try reverting your changes in settings one by one and thus find the culprit. GreyBOI said: They have been able to level up before, but now it doesnt work. They are able to launch the level up screen, but it's missing things, not able to roll HP, and one guy had (undefined) as the only thing added. I have tried to make a copy and it didnt work.  I'm using the base 5e and Curse of Strahd template, but I have often tried messing with the settings to change things. Anyone have any ideas?