Transaction deserialization failed

[Pz9524]

Attempting to create the raw testnet transaction fails in step Attaching reference,there is an error return {"code":-22,"message":"Transaction deserialization failed"}.
My operation used JAVA String reference = (String) client.invoke("omni_createrawtx_reference", new Object[]{opreturnResult, toAddress}, Object.class);
Is there any problem in my code? Help me @petertodd