addons.opera.com checks your User Agent string to figure out which browser you are, and adapt the results accordingly. I clicked "Get extensions" in my Opera 12.17 (for Linux) menu now, and I'm transported to https://addons.opera.com/en/extensions/. Here I see various extensions, but they're all for Opera 12.
Have you by any chance changed the User Agent string, or made Opera mask as Chrome or Firefox? If so, that would make the site think you're using a non-Opera browser, and will serve you content for the newest version of the browser.
Having Opera 24 installed on your computer shouldn't matter, as long as you access the site in Opera 12.17.
"Get it anyway" means that you can download the content, even if it isn't made for the browser you use.
Thanks a lot. That was it, identify as firefox, although I don't recall making this change. By the way does the extension "go back" work for anyone in 12.17? I would love for that one to work, or is there an extension expert around who could have a look an try to make it work. Would be so cool
