Same issue. Has happened several times before during the past 6 months but it seems like this 'feature' is not going anywhere.

35.0.2066.92 & Windows 10 64-bit (WoW64)

Edit: Possibly triggered by copy & paste but only occasionally.

Opera 20+ series is complete crap. Pretty much all things that have made Opera good are gone. I have that plague on my laptop but using 12.xx in my main PC. Sometime after the updates stop coming to 12.xx it's probably time to switch.

Last time I made a switch I think it was from Netscape Navigator to Opera and I have been mostly happy even though there were a few rather unstable versions along the way. And that switch was made back on like.. 2003? Can't remember exactly. The new chosen path really makes Opera a very, very dead option. I'm guessing the ONLY thing they care about now is mobile phones and they want to build a generic version around that.