Your image shows the only capture to fail was #274. All the rest look fine. So im not sure what you mean all are failing?
If #274 is https://www.youtube.com/watch?v=sEhy-RXkNo0 then that downloads fine here.
Ensure your using the latest version 22.214.171.124 (Get Support) and have the latest page extraction engine which should download automatically if you have Get Support > Check for new version on.
You can check the version of the engine by going to Settings > Internet Downloads > Advanced > Page and the title should say 2016.03.14.
If your still having issues provide the url of the page hosting the video and your debug logs when you try and capture it by following these instructions: https://support.jaksta.com/discussions/topics/6000009063
To clear the Network Monitor is installed but not loading error - uninstall the Network Monitor from add/remove programs. Reboot and reinstall from the settings > internet downloads. Would recommend you to use winpcap instead of the network monitor unless you need to capture over vpn.
Please provide debug logs as per https://support.jaksta.com/discussions/topics/6000009063 so we can see what is causing the extraction error on your machine.
I have uninstalled network monitor, reinstalled winpcap, and tried again to download a video. I tried with auto and manual from the guides menu, and copying and pasting the video page address. Attached is the log zip file.
I thank you for your patience.
Your machine has expired google certificates on it that are stopping JMR connecting via https.
This will show you how to fix it:
I am trying to download videos, none of the websites that I've tried are working. I've tried youtube,
dailymotion, vimeo. All say the download completes, but has 0 bytes and an (error).