Actually I have not downloaded water and mountain color wallpapers; so why can i remove them but not others. And i have set a wallpaper for my desktop, and the wallpaper exists in the wallpaper setting of opera; but i can't remove it either. It's not the opera wallpaper and as you said, i should be able to remove wallpapers which are not from opera!!

I enabled the built-in VPN of opera, but after waiting a little (VPN is temporarily unavailable. Opera is resolving the problem) message was displayed. And the VPN doesn't connect at all. What should i do? I'm using the latest version of opera.

When i enter the wallpaper settings, i only can remove water and mountain color wallpapers (when i hold the mouse pointer on these two wallpapers, X mark appears at the top right of them). But when i hold the mouse pointer on other wallpapers, the X mark doesn't appear at the top right of other wallpapers in order to remove them. Is this a bug or what?