I have double checked the channel permissions, and I have found that the bot itself, the bot's role, and our server bot role all have these permissions, and it still gives me this error. Not even giving the bot admin privileges fixes this.
When the bot posts a new "Weapons Experimentation" message, there is no description of what weapon is actually available. This seems like a defect since the other dispatch messages all have a body listed with them in the bot.