This is almost certainly because you have placed something way outside the Board Outline. Check **Design Manager > Components** to find it.

@andyfierman No I've got one PCB that has started doing the same thing recently.  I have trawled everywhere to find something off-piste but can't.  Oddly enough it's the same PCB that sometimes reports zero components in my latest bug report.

Press hotkey K , find out what objects offseted with the center.

we don't know what happen in this object yet.

Hi. Thanks very much for the quick replies. After pressing K, I was faced with (what I thought was) a mostly empty page:  However, when dragging a big selection rectangle in the "empty" part on the left, the right pane said "Selected object : 1" and " Via properties ..." So even though I could not see it, I pressed the "Delete" key then "K" again and now my PCB is centered again as expected. I don't know how that via was created in that corner, but my problem is solved and most probably it was my mistake. Thanks again and sorry for the silly question. KR, V.

PS : oh, and by the way, Andy, "Design Manager > Components" was of no help, as it was not a component... But thanks anyway :-).

Sorry, I  forgot to say do the K hockey thing first. It may have shown up checking either the nets attached to each component or, if it wasn't connected to anything else, just checking for an unconnected Net because EasyEDA auto assigns netnames to everything that can form part of a net.

A quick fix is to make a backup copy of the pcb then, in the original PCB, press the K hotkey then select and copy everything that is part of the **original** pcb. Then select **everything** in the original pcb, delete it and then paste your copy of the wanted pcb back onto the canvas. Check it, save it. Done.