Such as "O3DS Beginner Version" in Taiwan/HongKong - which has 9.7.0-??J with NO Internet access except FW upgrade.
In these cases, Fasthax works but UDSploit doesn't.
So I believe it's an incompatibility of UDSploit.
This is because UDSploit and Fasthax have different ways of entering. Also, UDSploit was never made to work with less then 11.3 because Fasthax work perfectly fine.
3ds.zip
Here are two releases of udsploit. One of them (Forked by a GBATemp's friend) worked for my O3DS on 9.5 and the other one is the official one (I don't know which is each file, but anyway try both. One of them might work)
Such as "O3DS Beginner Version" in Taiwan/HongKong - which has 9.7.0-??J with NO Internet access except FW upgrade. In these cases, Fasthax works but UDSploit doesn't. So I believe it's an incompatibility of UDSploit.