Originally Posted by baileyscream
you cannot downgrade to 3.56JFW unless you run it in mfw builder to create a downgrade firmware with the downgrade hashes.
it was made for 3.55cfw users to upgrade to 3.56cfw but the jfw was rubbish and you get stuck in it (you need a hardware flasher to downgrade to 3.55 so you can update or you brick)
as the o/p has run min ver checker and it has told him 3.56 is his min then creating a downgrade 3.56JFW is suicide as he will be unable to put 3.56ofw or update higher and his system wont allow 3.55fw or below so he needs to wait and see if the 4.21 cfw is real or not (the one multiman has been prepared for)
Thank you for this information.
Good luck to op.