Hi @gregtd , this message is coming from the site, not from Opera. So you have to ask the maintainers of the site why you're not allowed to download the file.

https://forum.vivaldi.net/post/183630 https://bugs.chromium.org/p/chromium/issues/detail?id=798492

A. It is not a problem, and B. if it were a problem it is in a cache file - go to Setting and empty your cache and it is gone.