The witness data + locktime at the end (hex):
0000000000000000
There are 8 inputs in the transaction.
Are you sure that at least one of the 8 inputs comes from a Segwit address?
At least one input must contain witness data!
I'm guessing this transaction needs to be signed in Legancy format.
They're all UTXOs from a legacy address so I figured that the witness array still needs to be the total length of the inputs.