Dear Ladies and Gentlemen!
The «interrupted: network error» problem has been reported often enough by plenty of people, for instance on Quora, RSSing, Sayugi, VPN Crew et al, as well as in several places here in the Opera user forums.
Given how many different people suffered from the browser's shortcoming over such an extended period of time, still experiencing the problem to this day in the current version of Opera (66.0.3515.72 at the time of this writing), there is no denying that the problem is on the browser's end and has nothing to do with the operating system, antivirus, firewall, ad-blockers, extensions, add-ons or other excuses and distractions that administrators and moderators like to use as a pretext for closing/ignoring/locking threads with respective reports prematurely. The fact that the problem is «old» and has still not been resolved makes it worse, not better, so instead of locking the respective thread, it needs to remain open for current and future users to add their observations, until the bug has finally been fixed or sufficient resources/VPN servers lead to its disappearance. It makes much more sense to have one place containing all the reports, than to force people to open another one each time just because moderators try to hide the embarrassment.
Yes, it now takes longer for the network failure to present itself, usually after hundreds of MegaBytes, mere seconds before finishing the download, but that's even worse than before, because more precious time is being wasted waiting in vain. Second, download speeds are often dropping over the course of a download, starting at 100 kB/sec, then slowly falling to 80, 50, 20, 10 kB/sec. Since this results in a long time before downloads finish, the risk of being affected by the dreaded «interrupted: network error» augments further.
To add insult to injury, the forwarding/rerouting of the scourge of the Internet, Google's goddamned Cloudflare ReCaptchas, often takes too long or does not work at all, because the site «could not connect to the ReCaptcha server». Since every idiot and their brother imposes that harassment on their visitors these days, even when/where it really is not necessary, this results in having to click even more stupid stamp-sized blurry pictures with tiny pixels of bicycles, buses and pedestrian crossings. And since this happens so often that one has to request/resolve a lot of that nerve-killing impertinence, the occasions where «your computer/network requests a lot of ReCaptchas, try again at a later time» become more frequent as well, prohibiting access to the download or website for a while.
All these problems seem to indicate if not a bug, then an insufficient quantity/structure of servers and bandwidth; the fact that they have not been resolved in years justify the suspicion that not enough servers and bandwidth might be to blame, rather than a bug that's being kept as a pet instead of being squished.
This is something that only insiders can tell for sure, but merely ignoring, blocking, closing and locking reports or blaming add-ons and extensions is no acceptable course of action and definitely no solution. After years of dealing with these frustrations, it is high time to finally take them serious and do something definitive about them.
Thank you for your attention, keep up the otherwise good work and have a pleasant weekend.