91001: Cannot enter presence in the channel's current state

A request to enter the presence set was rejected because the channel was not in a state that permits presence operations, such as a channel that is detached, suspended, or failed.

What you should do

Enter presence once the channel is attached. If the channel is detached, reattach it; if it is suspended, wait for the connection to be restored, after which the SDK reattaches automatically; if it has failed, resolve the cause shown in its error reason before reattaching.

Why it happens

Presence can only be entered on an attached channel, and the channel was detached, suspended, or failed at the time.

What you'll see

The error is reported with code 91001 and HTTP status 400. The message is of the form unable to enter presence channel (invalid channel state: <state>).