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

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

Hello, we do not affect the download speed.

Hello, please give us more details.

Hello, install the Savefrom.Net extension, after installation on each video there will be a download 

button: https://en.savefrom.net/

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

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

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

Hello, it's not our fault that youtube decided to get rid of 3gp . There is nothing we can do about it.

Здравствуйте, чтобы Вам помочь, нам нужна от Вас информация о вашем браузере и установленном расширении.
Подробно Вы можете посмотреть здесь, скопировать, и прислать нам: http://ru.savefrom.net/user.php?info=1
Так же пришлите нам несколько ссылок на файлы которые у Вас не скачиваются.

Для большего понимания вы можете прислать скриншот экрана с ошибкой.

Спасибо за обращение в поддержку Savefrom.Net !

Hello, send screenshots of this ad.

Hello, please give us more details.

Hello, in order to help you better please, let me know me the name and version of your browser and version of the extension,
all can be found using the following link: http://en.savefrom.net/user.php?info=1