(previous post was for a friends O3DS, this one is related to mine)
Was trying to downgrade my N3DS XL from 9.8 using sysupdater, but kept running into that "failed to get" error. Switched to safesysupdater and it was maybe 10 files into patching, then native firmware, then another file, and then the normal DS "error has occurred screen" came on.
It rebooted after I took the SD card out but it's just loading forever if I try to access System Settings/etc. Disappointing - will try to get back into browserhax to try again...
edit - Just black screens if I start it with an SD card in it. Pretty sure the advice for me now is to try recovery...? So much for safesysupdater!
the thing with the blackscreen with the SD card in happened to me.
to get out of that, i went and deleted the extdata folder inside the Nintendo 3DS folder. from what i read, this was caused if you ever had installed menuhax earlier at any point (i had it when i started the procedure). deleting extdata gets rid of any theme data and completely eliminates the old menuhax and the system will start again.
you can just redo menuhax with browserhax after that.