Error during registration: 'NoneType' object has no attribute 'id'

[NMertsch]

A participant attempted to register with valid ticket information. The attempt failed with this traceback:

2025-06-23 15:56:34,036 - europython_discord.registration.cog - INFO - Assigning nickname '<REDACTED>'
2025-06-23 15:56:34,388 - europython_discord.registration.cog - INFO - Assigning '<REDACTED>' role_names={'PARTICIPANTS', 'Onsite Participants'}
2025-06-23 15:56:34,388 - europython_discord.registration.cog - ERROR - An error occurred!
Traceback (most recent call last):
  File "/home/bot/.venv/lib/python3.11/site-packages/discord/ui/modal.py", line 189, in _scheduled_task
    await self.on_submit(interaction)
  File "/home/bot/src/europython_discord/registration/cog.py", line 97, in on_submit
    await interaction.user.add_roles(*roles)
  File "/home/bot/.venv/lib/python3.11/site-packages/discord/member.py", line 1077, in add_roles
    await req(guild_id, user_id, role.id, reason=reason)
                                 ^^^^^^^
AttributeError: 'NoneType' object has no attribute 'id'