For some reason, channel is undefined when it reaches this line of code, so it cannot get channel.id . This error looks like it happens inside the discord.js library itself.

It looks like the last piece of your code that ran was events.js line 198. Can you post that part of your code file and the nearby lines?

Do you need to pass a channel parameter to a function you are calling?

This could be because discord.js v11 is deprecated, and you should be using discord.js v12. Check out Updating from v11 to v12 | Discord.js Guide for how to migrate.
Of course it could be something else