This is my working folder:
Running the "DSP20thJuly2022.exe":
I have selected the default European theatre and plane-set.
The planeset is one that uses the old 150 weapons so I need to load them by clicking the yellow button
Now they are loaded and I can click the launch button:
It is best to choose a single mission and set it up before flying. Many of the theatres do not have associated careers.
I chose an intercept in a Mustang: