Cannot send to channel usually appers when the channel is moderated (+m) OR when you are banned from the channel.
In the +m mode, only @Ops and +voice can talk. The rest will not be able to. If you are banned, then you cannot talk at all (some IRCds allow +voices and @Ops to talk, even if you aer banned).
Click here for a post about file sharing (which is not mIRC's function!)
Zyzzyx.
