You either have photos stacked (so you should expand all stacks), or you havea filter turned on, so you should turn off the filter.
You have 2065 photos that are in stacks that have been collapsed, meaning that those pictures are not currently visible in 'All Photographs'.
You could use 'stacking>expand all stacks' to open them all if you wanted them to be visible.
Thanks a lot. Now it works.