Cannot read property 'then' of undefined

[ghost]

I have a small problem with running the bot.
It displays this error after running.

Uncaught Promise Error!
TypeError: Cannot read property 'then' of undefined
at CommandoClient.destroy (/home/kropix-server-3/Komugari/commando/client.js:168:18)
at Promise.catch.e (/home/kropix-server-3/Komugari/node_modules/discord.js/src/client/Client.js:240:12)
at
at runMicrotasksCallback (internal/process/next_tick.js:122:5)
at _combinedTickCallback (internal/process/next_tick.js:132:7)
at process._tickCallback (internal/process/next_tick.js:181:9)
at Function.Module.runMain (module.js:696:11)
at startup (bootstrap_node.js:204:16)
at bootstrap_node.js:625:3

Could someone help me with this problem?