# 90001: Channel in an invalid state for the operation

Identifier: `channel_operation_failed_invalid_channel_state`



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](https://ably.com/docs/channels/states.md) 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.