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

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

¡Hola! Nuestra ayuda será más efectiva si copia y nos envía información sobre su navegador y de la extensión Savefrom.Net:
http://es.savefrom.net/user.php?info=1
También necesitamos algunos links que no pueda descargar (para probarlos).
Para tener mayor idea del problema, será de gran ayuda ver una captura de pantalla en donde se muestre el error.
Esperamos su respuesta, ¡gracias por ponerse en contacto con nuestro equipo Savefrom.net!

Hello, please give us more details.

Before downloading a video, hold down the <Alt> button and then the download button.

Hello, tell us the name of your browser?

Ок.

This method works if you do it right.

Go to Tampermonkey settings, enable Advance settings mode -> Downloads BETA -> Download Mode: browser api.
Restart TM – everything should be working.

Remove Tampermonkey and install the Chameleon extension:

Google Chrome. First 1 then 2.
1. Install the extension Chameleon: https://chrome.google.com/webstore/detail/chameleon/dmpojjilddefgnhiicjcmhbkjgbbclob?hl=en-US
2. Install the extension Savefrom.Net: https://addons.opera.com/en/extensions/details/savefromnet-helper/?display=en

Hello, have you configured the Tampermonkey extension?

Or set up Tampermonkey does not help?

Hello, the site is working properly, the problem of downloading from behind the Safari browser, with this we unfortunately can not do anything.
You can use another browser or the Televzr application.