I’ve tried several occasions to download LibreOffice, using Chrome. The download just never began at first. When I tried again using Edge, I received the error “can’t be downloaded securely”.
I’m running Windows 10, version 21H2. I’ve adjusted the feature in apps & features to allow downloading from “anywhere”. Still nothing.
In Windows 10 Settings, if you have set Apps>Apps and Features to "Select sources for getting apps: select “Anywhere”.
I assume that you don’t have Windows 10S. That won’t allow downloading of apps from anywhere except Microsoft Store.
You are downloading from www.libreoffice.org I assume and not another site. And that you clicked the Download button, not Torrent. You could click on info and choose a mirror in case the mirror selected automatically is blocked on your computer
Run through the steps in this question on Microsoft Community, you might need to follow through to the second page. If something works, can you post the answer back here? https://answers.microsoft.com/en-us/protect/forum/all/libreoffice-cant-be-downloaded-securely/7e1eb38b-d737-4b1b-a174-f06f41ddb1a4?page=1
It could be an anti-virus settings. You could check in the conveniently situated Start menu > Settings > Update & Security > Windows Security > App & Browser Control > Reputation-based protection settings > Potentially unwanted app blocking > Protection history that Defender hasn’t blocked the download
