When I download a you tube MPEG4 I get the message:- youtube 2.mp4" could not be opened. The movie is not in a format that Quick Time understands You may need to install additional software to open this type of file. What do I do now?

Hmmm. I would try Perian.

http://perian.org/

From what I've heard, YouTube is getting more serious about enforcing their own ToU which have never allowed downloads. Maybe your problem is the result of that?

I've avoided QuickTime for years. Total junk. Try the free VLC player, here:

http://www.videolan.org/vlc/index.html

softwater wrote:

I've avoided QuickTime for years. Total junk.

Why would you consider Quicktime as junk? I have never had a hiccup with it and even as a video editor, it is far more advanced than a lot of third party rubbish,

Pete

"That's a bit sad, Babowa. My connection is sometimes so slow it's better to download and watch later. thanks for the info."

What is sad? The fact that many think it is okay to download other people's work without their permission?

I am just another user, so you would need to address your concerns with YouTube. I'm sure you mean no harm, but it is their site and they make the rules (although some people choose to ignore them):

Content is provided to you AS IS. You may access Content for your information and personal use solely as intended through the provided functionality of the Service and as permitted under these Terms of Service. You shall not download any Content unless you see a “download” or similar link displayed by YouTube on the Service for that Content. You shall not copy, reproduce, distribute, transmit, broadcast, display, sell, license, or otherwise exploit any Content for any other purposes without the prior written consent of YouTube or the respective licensors of the Content. YouTube and its licensors reserve all rights not expressly granted in and to the Service and the Content.

Just googleYoutube terms of service....... 😉