From Undernet's #Class:
<Class> "4. -Target change too fast- This message means that you are either sending too many messages to many different people, trying to join too many channels in a short period of time, or using the old /onotice command. Use the /notice @#channel command (discussed earlier in Session C)instead of /onotice. (F11)"
That said, either join fewer channels automatically, or else put a delay on your channel joining.
Example:
on *:connect: {
if ($server == yourserver) {
set %i 1
.timerjoin $lines(MyChannels.txt) 2 join $read(MyChannels.txt,%i)
.timerjoincnt $lines(MyChannels.txt) 2 inc %i
}
}
If you turn off mIRC's join channels on connect/reconnect option, this should work for you. Place all your channels into a text file called MyChannels.txt in your mIRC folder (one channel per line with # signs). It will join one channel every 2 seconds after connecting.
Make sure you replace "yourserver" with your server. If you don't know the correct name for it, use "//echo -a $server" while you are connected to it.