I usually connect a monitor to my laptop while I'm working so I have two screens, with the monitor set as my primary. But I've found that if my last session of Opera was displayed on my laptop (when it is the secondary monitor) and I use my laptop without the monitor, Opera will 'open' on the second screen even though my laptop screen is now the primary screen and the only one connected. As far as I can tell there is no way to actually access the Opera window without plugging in the monitor again. Opera will appear on the taskbar, but there is no way to interact with the window itself, only with the taskbar icon (unless you plug the monitor back in).

@zuo Yeah, this is exactly the same problem, and currently the only solution is to just plug in another monitor (or two, if it was on your third monitor). It's like Opera displays to the 'segment' (monitor) an the extended display it was last on, even when 'segments' are removed.

@quik I plug a monitor into my laptop, and set my monitor as the primary and set it up so the display extends onto my laptop's screen. However, when I unplug my monitor, my laptop's screen switches back to being the primary (and only) display, and the opera window, which was on the second display (my laptop screen) remains on the second display, even though there is only one. Without plugging in another screen, there is no way to use the browser or access it. I recently started plugging two monitors into my laptop, and found the same thing happens. Opera continues to display on whatever display it was displaying on when the monitors were connected, even when the number of displays is decreased to two or one.

I usually connect a monitor to my laptop while I'm working so I have two screens, with the monitor set as my primary. But I've found that if my last session of Opera was displayed on my laptop (when it is the secondary monitor) and I use my laptop without the monitor, Opera will 'open' on the second screen even though my laptop screen is now the primary screen and the only one connected. As far as I can tell there is no way to actually access the Opera window without plugging in the monitor again. Opera will appear on the taskbar, but there is no way to interact with the window itself, only with the taskbar icon (unless you plug the monitor back in).