That's very strange. On all older versions (11.64, 12.14, 12.17) dragging links to the address bar works as simple copy/paste, but on Opera 26 beta, 26 developer it works just as you describe and I didn't tinker with this setting (if there is one of course :P)

For me clicking on image and dragging only copy the image address to address bar. For opening image in a new tab I simply click on it using middle mouse button.

I've tried on 11.64, 12.14 and 12.17 and dragging texts/links to the adress bar only paste them there. If I remember correctly in the past it worked as Dave described. Maybe Opera ASA disabled this for security reasons like with autopasting from clippoard?

Guys do you now how to make Disqus notification bubble to work the way it does in Opera 25? When you press it, it should dim screen and white board should slide from the right side of the window showing recent conversations. On Opera v12.17 (tried also on on v11.64) pressing the bubble only dims the screen and that's it.
Maybe you now some override, user script or extension that deals with this issue? I tried asking Disqus technical support, but from their response I conclude they rather don't care about Opera.

You can also remove everything in cache folder from Opera and cookies from problematic websites. It's also working quite good. Disabling webfonts should be the last resort as many websites will look ugly without them.

I can confirm that I also get 403 error on Opera 12.17 on Windows 8.1 but I don't know if it's a temporary thing or not as I don't use this forum.

Sorry to hear that. I don't have any other ideas. Here on v12.17 Tumblr works. You can try moving your existing Opera profile to another computer and see if you still got the issues (but remember to clear cookies and cache).

On my laptop Opera 12.17 with mail client enabled, irc client, all the extensions, etc. is still faster than new Opera 25. There are sites with much js that had slow downs, but when I look at bigger picture (usability, features, ease of use, productivity) I can't imagine surfing internet without Opera 12.
Easy access to emails and rss. Auto refreshing previews of the sites I frequently open in speed dial. Keywords for the bookmarks that let me write 2-3 letters to get to any bookmarked website. Tab previews, skins and customizable interface, with custom buttons. It's just perfect, so PLEASE PLEASE MAKE PRESTO OPEN SOURCE

I'm using Opera v12.17. For some time I was using oGet extension to use different downloaders (OrbitDownloader for example) with Opera and it tried to download fonts from websites and many of them gave me silly looking fonts or symbols and other rubbish.

As EagleGet get the job done without downloading fonts I basically have no issues with webfonts now. To tell the truth in many cases they are more clear and better rendered than on new Opera 25.

It may be a long shot, but I had so much issues with new ssl/tls settings remotely send by Opera Team that your issue might also be resolved changing these settings.

In address bar type:
opera:config and search for ssl,
disable "Enable SSL v3" and save,
search tls,
enable only tls 1.0 and save,
now clear cookies for tumblr website and restart Opera.

I hope it will help you.