Can't say, it opens player

Yeah, my bad on that suggestion.

@donq If you copy the link, open a new tab and paste-n-go the link in the new tab's address field, does the download complete properly?

Can't say, it opens player then - from forums page, I download it by right-click, Save linked content as.... Not so important to reconfigure someting

What about if you click the badge at the left of the address field while on this page, goto site settings and enable insecure content for the forums and then click on the link?

Then everything works beautifully (file completes), thank you

Yes, Opera should have some option (dialog) to allow download such files easily. Protecting users from themselves is often good idea, but overdoing or oversimplifying it usually not.

Opera could have some UI for this similar to Chrome. When insecure content isn't allowed for a site by site settings, in Chrome's download bar, you'll get a "Can't be downloaded securely" error with only a "discard" button. But, you can click the arrow next to it and choose "keep" to allow the download (without adding an insecure content override to the site's settings). Then, it'll download successfully. You have to do it from the download bar though. If you do it from the chrome://downloads page, after you click "keep", a dialog will pop up with an error that has "keep anyway" that you can click. But, clicking it doesn't do anything. Opera of course shouldn't copy that quirk.

What about if you click the badge at the left of the address field while on this page, goto site settings and enable insecure content for the forums and then click on the link?

I think that should help. This is not a problem and not a bug at all. This is now standard behavior for browsers on the Chromium engine when trying to load HTTP content through an HTTPS source. You can add a private exception through the bagde or through the opera://settings/content/insecureContent page. On that page, you can even register the https://* mask for all sites as an exception and forget about this problem. From a chrome security point of view it's not quite right, but it's convenient.

What about if you click the badge at the left of the address field while on this page, goto site settings and enable insecure content for the forums and then click on the link?

@mechkalito I've just tried here with Opera Developer 88 and the download didn't complete. When it reached 100%, the estimated remaining time turned in a ? (interrogation mark) and the download didn't finished.

Same behavior here.
Interesting is that dev console tells me:

Mixed Content: The site at 'https://forums.opera.com/' was loaded over a secure connection, 
but the file at 'http://s141218.gridserver.com/mixes/todosTenYears/todosTenYears.wav' was loaded over an insecure connection. 
This file should be served over HTTPS. This download has been blocked. 
See https://blog.chromium.org/2020/02/protecting-users-from-insecure.html for more details.

This is strange, it seems like blocking happens at the end of file download, not before.

On the same note, I'm having the same issue on different PCs, were I also use Opera.

@mechkalito I have the same issue. did you find a fix?

I didn't.

@nicolefresher3221 said in Download of large files won't complete (stuck at 100%):

@mechkalito I'm facing the same issue and then I reinstall the browser and then I tried and that time the download finished properly....

Didn't work for me. Fresh Opera installation on fresh OS installation has the same issue.

What does cause such behavior - unfortunately I have no idea.