You can not not share a You Tube inside an Adobe Connect meeting room and have consistently, reliable results. Two options are:
You can use the Web Links pod to force attendees’ browsers to open a designated URL. Here's how:
Or you will need to convert the YouTube to an MP4, then upload the MP4 file to a Share pod and play the file.
I've done it the past with this technique:
To successfully convert a YouTube video and a MP4 so that it can be played AND recorded inside an Adobe Connect Meeting Room, go to:
Install the Free YouTube Downloader program.
Enter the YouTube URL or selected file, and select Output format: No Conversion (MP4)
Go to Adobe Connect Meeting Room
Open Share Pod
Browse for File, Upload and Done!