Hello, what exactly is not working?

Describe in more detail.

Hello, we have no direct relation to Tampermonkey.

Write to them in support.

https://chrome.google.com/webstore/detail/tampermonkey/dhdgffkkebhmkfjojejmpbldmpobfkfo/support?hl=en

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!

Здравствуйте, с какого сайта вы скачиваете?

Hello, now the Savefrom extension in Google Chrome browser works through Violentmonkey.

https://en.savefrom.net/user.php?vid=387#10

Hello! Due to the recent youtube changes, both our website and the add-on are enable to download in 720p.
We are trying to bypass it, but with no luck yet. For now, we can recommend switching to Televzr app, that can download in 720p and higher:
https://desktop.televzr.com/#

Hello, in Opera browser, install the extension for this link:

https://addons.opera.com/addons/extensions/details/savefromnet-helper/?display=en

Hello, the version of the program?
Your OS.
Send a link to the playlist that you can not download.
Do you use any proxy?
Are you using a paid Ummy Video Downloader version?
Please, send some screenshots of the app showing how you download a video.

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, describe in more detail.