Yes, for ME 6, we only have old RGN firmware. However, it turns out that you don't need to do these in your case since HP includes a full SPI/BIOS image at their support website. First of all, before you do anything, make sure that you have kept a full SPI/BIOS backup via "fptw -d backup.bin", just in case we need it.

I took 7H3_0122.bin and cut some irrelevant data from the end (0x800000+) because for some reason HP includes another ME firmware blob there, probably for some flashing tool they use, but we must delete it for FPT/Programmer use. I've also extracted the ME region only from 7H3_0122.bin which you can flash via "fptw -me -f 7H3_0122_ME.bin" followed by "fptw -greset". Don't forget to set the jumper back when you're done. Afterwards, you shouldn't see the error anymore. If you do, try removing all power (PSU cord) for 1 minute and try again.

If that doesn't help either, it means that the BIOS is problematic, not ME. In such case, you can re-flash the entire SPI image via "fptw -f 7H3_0122.bin" (the one attached which has been cut, not from HP softpaq) followed by "fptw -greset".