JDA (the Discord library wrapper) was too old to handle news channels.
The presence of a news channel caused the bot to crash and/or not start
properly.

JDA has been updated to the last 3.X.X release. The 4.X.X branch cannot
be used as it would break setting roles to emotes, thus rendering the
bot useless.

There also has been a minor fix for a bug which prevented errors from
being shown if there were no roles in the add/remove commands.