Having the exact same issue with Opera One. It crashes on start up every time. I have tried uninstalling and reinstalling. This only works for my first time opening the app. I have to reset everything and log into all my stuff after reinstalling, but the moment I launch the browser a second time after that initial post-reinstall launch, it crashes immediately again. This is pretty catastrophic, and it didn't start happening until these past few days. Please fix this immediately Opera. I use a lot of things on this app for work, and I need it to reliably function.
I have read several fixes involving extension settings and stuff, but the folders everyone points me to to remove files from don't even exist, despite me following the exact pathing. What the heck is going on after the last update that is making this happen? Because I didn't change anything to cause this.