Hi Michael,
It's not immediately clear to me where that screenshot is being taken. It looks like it is the floorplan with a layout or a master set as the reference in the background, as there is no paper area defined, but you wouldn't have the message about the master on the floorplan!? If it is a layout, where is the drawing frame for that placed view, just to count it out?
It looks like some kind of rogue origin, but the origin point doesn't seem to be included in the zoom-to-extents definition so should be ignored.
Where is the origin in the master that is applied to that layout? Perhaps you have a hotspot on there also?
I suppose it could also be part of a library part used on the master. Does it occur even on a new blank master?
We need a little more info on the specifics to get to the bottom of this.