mBlock update firmware
Usually by Firmware we understand "a program that was prepared by company that produced the hardware and that is necessary for that hardware to work correctly". I suppose that developers of mBlock are smart enough not to allow people to "brick" their Arduino's. I suspect that ether you updated your bootloader (it's also a firmware) to latest version or simply nothing happened. In both cases your device should be operational. Burning a bootloader onto an Arduino is not as hard as it seems so even if you broke something you should be able to fix it.