Re: Error Message in project file

> with "D:\Program Files\GNAT\GtkADA";

This is wrong, you need to specify a gtkada.gpr file, NOT a directory.

> gprbuild -d -PE:\ada\project\Algemeen\empty.gpr -s -j4
> gprbuild: project file "E:\ada\project\Algemeen\empty.gpr" not found
> in
> .;;D:\Program Files\GNAT\2012\share\gpr;D:\Program
> Files\GNAT\2012\lib\gnat

That's because GPS could not load your project file in the first place because
of the above error.

I would suggest you read the GNAT documentation on project files to understand
better how these work. See e.g. the gprbuild documentation from GNAT GPL.

Arno