You need to figure out which one of your browser extensions was recently updated that is now asking you for additional access to the browser. I don't know how Opera handles this, so you may well have to disable all of them and then enable them all one at a time until you start getting that error. You do want to be careful since Opera is now based on Chrome and Chrome's extension ecosystem is littered with developers who get offered a couple grand for their extension only to have it turned into some kind of spam pumping malware. So once you figure out which extension wants more permissions, be sure to do a quick bit of googling to make sure that others aren't reporting search hijacks, or ads being inserted into the text of sites,etc.