But still wont work if you're using a SegWit wallet which is the default in that version (and the only option for new wallets in the GUI).
Sign (from 'tb1qw2es79xv7c8fyjtzuvfw40g6zxxun7puwtqlp0'):
signtransaction("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", privkey="cUoYdz49ZCG2UijNrwisrJESZgKvBrS15F9Q7brQrVLu9jZ3jzSY")
Result (still unsigned):
"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"
Other more complex scripts cannot be signed atm without a wallet.