For all those having issues with logging in and no captcha, until fixed, do this..
before you login type in /debug
into the room
on the debug window that opens, go to debug
menu then select YMSG Decoder
and ALL Packets
if not already selected.
Then connect as normal with this debug window open and you will see a lot of data appear in it, when you're suppose to see a captcha.
resize the debug window a little if your vertical scrollbars are not showing on it.
Then scroll down the debug window and you will see a new large captcha link like below,
copy and paste it into your browser and enter the captcha and yahelite will automatically join chat.
This is simply a workaround to yahoo's latest chatroom changes last night.