You folks are all over the map on this "issue..."
The so-called "black bar" is simply the bottom edge of the 3d-View Window. Normally, the Window00 section is configured such that the lower edge of the 3d-View Window falls just
below the top edge of the 2d panel.
It is done this way for two reasons.
First: Performance - there's little point rendering pixels that're covered up by the 2d panel!
Second: Point of View - having the 3d-View Window sized this way allows a better view of the taxiway/runway, and also moves the horizon line to a proper perspective with respect to the 2d panel.
To summarize the "issue," if you see a "big black bar" at the bottom of the screen, it simply means that your 2d panel isn't displaying!!!

Shift-1 will turn it back on...
Keep in mind that the entire camera/view system in FSX has changed. There are now multiple "sub-views" for each of the previous S views.
I would urge everyone to simply sit still and cycle through all the view options, beginning with the VC (default) view.
Press the A key to cycle through all of the "Cockpit View" cameras.
Now, press the S key to switch to the next major View Category, and again cycle through all the sub-view options with the A key.