Downloading problem

Hello, I have the same problem.

My Browser informations : 

Browser: Chrome 61.0.3163 Windows 10
User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.31 Safari/537.36

Screen of problem ( Youtube ) : 

And when I look the Javascript Log, I have this : 

Thank you for help ! :)

Hello, Do you download via the extension SaveFrom.net Helper or the website SaveFrom.net?

Could you please send a few links you can't download. We will check it out.

According to the information you do not have an extension.

Install the extension here in these links.
Google Chrome. First 1 then 2.
1. Tampermonkey black: https://chrome.google.com/webstore/detail/tampermonkey/dhdgffkkebhmkfjojejmpbldmpobfkfo?hl=en
2. Savefrom.Net: https://download.sf-helper.com/chrome/helper.user.js?ts=1455972944179

Hello,

I don't now, I downloaded it a long time ago ^^

I have the extension Tampermonkey and the app.

I have this : 

Reinstall the extension, delete what you have installed and install on the links that we gave.
Describe your problem in more detail.
Could you please send a few links you can't download. We will check it out.

Can you watch youtube videos in the browser before you are trying to download it?

Hello,

After reinstall, it's good ! :)

Thanks you very mush !

Thank you for using our extension SaveFrom.net Helper