So tell me, you do have a second drive (probably a regular hard drive) where you'd like to save these files?

Install the "Video Downloader All In One" extension (http://addoncrop.com/video_downloader_all_in_one/) -- works like a charm for me.

I opened every one of those YouTube links and was able to watch each video (I'm using the latest version of Opera on macOS Sierra).

The trick is to first download the video to your hard drive and watch it there. If I tried to play those videos listed above inside the browser I got the same errors you all were seeing. But if I downloaded the video first, it played just fine.

If you install the "Video Downloader All In One" extension (http://addoncrop.com/video_downloader_all_in_one/), then go to the YouTube video page, an additional green Download button will appear just below it. Click it, and it will download it to your hard drive and it will play just fine.

Hope this helps!

Dan

Once upon a time....there was a wonderful extension for that formerly wonderful browser Safari.

It was called Glims (https://www.macupdate.com/app/mac/27708/glims for the full list of features). But, alas, it no longer works and they've stopped development on it.

Now, most of these features have been incorporated into the newer versions of Safari. All but one: Dated download folders. This feature would create a new folder inside your Downloads folder with that day's date every day and anything you downloaded would be placed there. That was my favorite feature.

Due to the ongoing suckiness of Safari (don't get me started...), I've switched to Opera, which I love. But I really miss those dated download folders.

Is there an Opera extension that will provide this feature? I know that in Preferences I can tell it to ask me where to save each download, then make a new folder for each day, but that's too cumbersome (for me, anyway). I searched all of the Opera extension pages but nada.

Anyone know of any extension that can do this? Any plucky programmers out there want to take a crack at it?

Dan

If you close the last tab/window the application Opera does stay open, it just has no window to show you. If you look on the Dock after closing the last window/tab you'll see Opera is still running. There should be a black dot under the icon. If there isn't, open System Preferences, click the Dock preference icon, and at the very bottom of the window make sure the "Show indicators for open applications" is checked.

To get a new Opera window just click the icon on the Dock and the still-open application will pop one right up for you.

Now, there are some apps (mostly Apple ones) that do Quit the application when you close the last open window/document (Safari, Preview), but Opera is much better than either of those

Hope this helps!

Dan