40000: Bad request

The request was rejected because it was invalid and could not be processed.

What you should do

Correct the request and resend it. 40000 is the generic code for a request Ably could not process, so start from the accompanying message, which states what was wrong.

Why it happens

The request was malformed or otherwise invalid in a way that doesn't have a more specific error code. The accompanying message describes the specific problem.

What you'll see

The error is reported with code 40000 and HTTP status 400. The message describes what made the request invalid.