This message occurs when either a channel is set to +m (moderated), meaning only voices (+) and ops (@) can speak, or you are banned inside the channel.
To check what the channel modes are, use /mode #channel. If 'm' is in it anywhere, then that is the reason. This should not occur for all channels. There's nothing you or us can do about it though, if it's set to +m then you need to be voiced/opped to speak, there's no other way. Try going to a different channel.