90001: Channel in an invalid state for the operation

A channel operation was attempted while the channel was not in a state that permits it, such as publishing or performing an action on a channel that is not currently attached.

What you should do

Refer to the channel's state and its error reason to see why the operation wasn't allowed. A failed channel does not recover on its own: address the cause reported in its error reason, often an authentication or capability problem, then call attach() to re-establish it. A suspended channel is re-attached automatically once the connection is restored. If you are releasing a channel, detach it first, since a channel can only be released once it can no longer receive updates.

Why it happens

The operation is only valid in certain channel states, and the channel was in a different one. Common cases are performing an action on a channel that is not currently attached, detaching a channel that has failed, or releasing a channel that could still receive updates.

What you'll see

The error is reported with code 90001. The message is of the form Channel operation failed as channel state is <state>; the server reports Unable to perform operation on channel: <name> (not currently attached) with HTTP status 404.