It's been crashing for me as well every time I click on a new tab or a link or whatever. And there is one travel site that simply refuses to update. It goes to the site, lets me log in, and when it tries to load the page, just takes me back to the login, and keeps doing this. Wanting to make sure it wasn't the site, I logged in through Firefox without a problem whatsoever. I really like Opera, but I can't deal with the constant crashing. Is this going to get fixed any time soon? I'm on macOS High Sierra v. 10.13.3.
Adding for posterity @avl that it appears that when a window's open for a while, even if the white bar does not appear (because I'm actively using that window), the display will become off-calibration with what's on the page, forcing me to move my cursor below where the link actually is to click on the link. The behavior fixes itself if I switch tabs.