Use the JapharFlasher, to restore the bootloader for your sim.
Remember that you can use only Ferrari Sim images, Kernel 2.6, with your box (images from 2011-2012).
If you want to upgrade to newer images, up to 2021 you need Kernel 3.2 and so swap your old sim to a new one that supports latest drivers from 2016/images etc.
TS