My Try:
{"method":"model.sale.sale.create","params":[5,"144d7342b0",{"shipment_address":17,"description":"","invoice_address":16,"lines":["create",[{"quantity":1,"unit_price":{"decimal":"200.00","__class__":"Decimal"},"description":"Stuhl","amount":{"decimal":"200.00","__class__":"Decimal"},"unit":1,"id":0,"discount":{"decimal":"0.00","__class__":"Decimal"},"product":3}]],"payment_term":1,"party":10,"currency":30,"sale_date":{"month":12,"year":2016,"day":28,"__class__":"date"}},{}]}

Error:
{
  "id": 0,
  "error": [
    "'unicode' object has no attribute 'iterkeys'",
    "Traceback (most recent call last):\n  File \"/trytond/protocols/wsgi/__init__.py\", line 55, in jsonrpc_app\n    response['result'] = dispatch(*args)\n  File \"/trytond/protocols/dispatcher.py\", line 158, in dispatch\n    result = rpc.result(meth(*c_args, **c_kwargs))\n  File \"/trytond/model/modelsql.py\", line 399, in create\n    super(ModelSQL, cls).create(vlist)\n  File \"/trytond/model/modelstorage.py\", line 87, in create\n    all_fields = list(set(chain(*(v.iterkeys() for v in vlist))))\n  File \"/trytond/model/modelstorage.py\", line 87, in <genexpr>\n    all_fields = list(set(chain(*(v.iterkeys() for v in vlist))))\nAttributeError: 'unicode' object has no attribute 'iterkeys'\n"
  ]
}