i got FW 9.9E :/I had the same issues as you were having with the failed to get cia info. I have been trying to downgrade for 2 weeks straight trying different versions of the sysupdater. i formatted my sd card, hard reset the 3ds, till eventually I used the safesysupdater and it worked first try. I just had to make sure I was connected to internet for it to work and check the md5 on its own then it said it was good to go and my files matched my 3ds version then it downgraded successfully.
n3ds small EUR
used menuhax 2.1
firm originally 10.3 down to 9.2
used safesysupdater v08
edit: also i did not use the ftbrony trick. i just went straight into safesysupdater
im trying to update to FW 10.3 and then use the safesysupdater for downgrade.
or should i use it directly for a downgrade?
is it possible to update my system with safesysupdater?