40010: Invalid channel name

The channel name in the request was not valid, for example because it was empty, contained characters that are not permitted, or used an unknown square-bracketed prefix.

What you should do

Use a valid channel name and retry. Names must not be empty, must not start with [ or :, and must not contain newline characters. See the channel naming rules for the full set.

Why it happens

The channel name in the request broke one of the naming rules, or a square-bracketed qualifier was malformed. This includes an empty name, a disallowed leading character, an unsupported qualifier or parameter in the [...] prefix, or an unparseable channel key.

What you'll see

The error is reported with code 40010 and HTTP status 400. The message is typically invalid channel name: ..., or names the specific problem such as Invalid qualifier in channelId; ....