Hello, please, send us more details regarding the problem.

For the better understanding it'll be great to see a screenshot with the error.

Hello! Our help will be more effective, if you copy and send us info about your browser and the Savefrom.Net extension:
http://en.savefrom.net/user.php?info=1
We'd also need some links you can't download (to test them).
For the better understanding it'll be great to see a screenshot with the error.
We are waiting for your reply, and thank you for contacting us Savefrom.net Team!

Hello, in order to download HD from Youtube you need to install our program Ummy Video Downloader: https://videodownloader.ummy.net

Здравствуйте, для эффективной помощи нам нужна информация о расширении и браузере.
Скопируйте и пришлите информацию указанную здесь: http://ru.savefrom.net/user.php?info=1

Hello, in order to help you better I need the following information.
Please, send me the information listed here: http://en.savefrom.net/user.php?info=1
Do you download via the extension SaveFrom.net Helper or the website SaveFrom.net?
For the better understanding it'll be great to see a screenshot with the error.

Hello, this site is not on the list of supported resources. The full list can be found here: http://en.savefrom.net

Hello, Yes, we are aware of this issue. And doing our best to fix it ASAP.
Thanks for using our resources.
Best, SaveFrom.net Team

Hello, thank you for contacting support in Savefrom.Net
This bug is known to us, we will try to fix in the nearby future.

Hello, Yes, we are aware of this issue. And doing our best to fix it ASAP.
Thanks for using our resources.
Best, SaveFrom.net Team

Здравствуйте, мы знаем об этом и делаем всё возможное что бы это исправить.
Спасибо что вы с нами и пользуетесь нашими ресурсами.
С уважением команда Savefrom.Net