GtkAda including in my Ada program

I installed a new version of the Ada computer and of the GtkAda library Now I have problems with compiling a program that was compiled correctly till now.
(compiled several years ago). What is the solution

Error message in the next cases:
No reference to GtkAda in main file or project file Literal String expected main
with GtkAda in main file nothing in project file File GtkAda.ads not found main
with Gtkada in project file nothing in main file Literal String expected project
with Gtkada.gpr in project GtkAda in main Literal String expected project
with Gtk in both files Literal String expected project

It seems that your build environment cannot find GtkAda.

How are you building it? With Alire? With GPRBuild? With GNATmake directly? If you could, please provide as much information as possible.

Thank you,
Fer

My operating system is Windows 11
I have installed Ada in the directory D:/GNAT/GPS. It is installed from
Releases ยท AdaCore/gnatstudio where an .exe file is to install the program. The directory was first completely emptied. (The older versions were also cleaned in the configuration screen). I have added the directory D:/GNAT/GPS/bin to the PATH : GPR_PROJECT_PATH. This version is 26.0w. The last version was 20.0w.If you need more information please specify.

  1. Remove D:/GNAT/GPS/bin from GPR_PROJECT_PATH
  2. Install GtkAda, e.g. under C:\GtkAda
  3. Add C:\GtkAda\lib\gnat to GPR_PROJECT_PATH

For execution the Path variable should contain D:\GNAT\GPS\bin;C:\GtkAda\bin