Ngrok errors '502 bad gateway'

Question

Quite new to using any sort of Web App stuff, and I\'ve been trying to slowly build a Facebook Messenger Bot. When I try to use ngrok I can\'t visit the address I\'m given,

Answer 1

It seems that this issue has now been resolved in the latest version of ngrok: https://github.com/inconshreveable/ngrok/issues/448

Basically, what you do is to specify that you are using https like this:

ngrok http https://localhost:54321 -host-header="localhost:54321"

At least, this resolved the issue for me. Replace 54321 with your actual port number.