Arduino DUE "Flash page is locked" error

Good day

I was working with my Arduino DUE an suddenly it got freeze, when i tried to download a program i got

"Flash page is Locked" error, I posted it in Arduino DUE forum, and gave me a solution changing some

parameters in packages>arduino>hardware>sam>1.6.x>platform.txt file, I tried but dindn't work.

Are There any solution for that?

Thanks in advance