See if this helps:
https://steamcommunity.com/app/1912410/discussions/0/581683736959040360/
Or try support:
https://help.minecraft.net/hc/en-us/articles/48756373908621-Minecraft-Dungeons-II-Error-Help
Support request:
https://help.minecraft.net/hc/en-us/request/new?ticket_form_id=360001225811