Thanks for jamie reply, i managed to fix the project.
I had to change some object declaration to class declaration,
and to comment out the override property from LoadFromFile.
(I had also to comment one line with an undeclared variable.)
The project compile and seems to run correct.
My conclusion from this, is that something in freepascal has changed.
In the past object could be used with virtual methods.
Now it seems that no.
Again, Thank you jamie very much for your help.
Without it i would be lost.