I saw that you have GPF when using jFiles.
Couple months ago, i also had that kind of problem, just to realize that in my application, which is multi-dll, in dll where problem occurs, I did not check the flag on global template: "This is the part of Multi-DLL program".
Compile goes without errors, as expected, but, when I call procedure where jSon is, entire application crash...I did not telling that is your problem, but worth of checking, if your application is multi-dll
Regards, Oggy.