Good news!
The problem seems to be the aircraft profile.
After deleting the c172.profile, I created and saved a new flight plan and it worked correctly.

Thanks for your help..

The aircraft profile....

With the aircraft profile empty (at least in profile window  ;)) there are no changes...

Thanks.
Log included...
As you can check in the screenshot the "Reverse" screenshot is disabled, "Edit" too....the only enabled button is "Fast", like if I were creating a new plan.

Here you have...

Hi, excuse my English.
I am using 4.0.0.238 and, after loading a flight previously created, the map shows the route correctly but the Flightplan window is empty.
Any idea?
TIA