Create Invoice API returns {"code":4,"message":"Invalid value passed for JSONString"}?

Create Invoice API returns {"code":4,"message":"Invalid value passed for JSONString"}?



Why do I get a {"code":4,"message":"Invalid value passed for JSONString"}?

{
"customer_id": "1305319000000146080",
"contact_persons": ["1305319000000146082"],
"invoice_number": "INV-00005",
"reference_number": "123459898",
"template_id": "1305319000000017001",
"date": "2018-09-12",
"payment_terms": 0,
"payment_terms_label": "Due on Receipt",
"due_date": "2018-09-12",
"discount": 0.00,
"is_discount_before_tax": true,
"discount_type": "entity_level",
"is_inclusive_tax": "false",
"exchange_rate": 1.00,
"recurring_invoice_id": "",
"invoiced_estimate_id": "",
"salesperson_name": "Online",
"custom_fields": [],
"line_items": [{
"item_id": "1305319000000146013",
"project_id": "",
"expense_id": "",
"salesorder_item_id": "",
"account_id": "1305319000000000388",
"name": "Hotel Room",
"description": "Hotel room",
"item_order": 1,
"rate": 120.00,
"unit": "Nos",
"quantity": 4.00,
"discount": 0.00,
"tax_id": "1305319000000062040"
}],
"payment_options": {
"payment_gateways": []
},
"allow_partial_payments": true,
"custom_body": "",
"custom_subject": "",
"notes": "Thanks for your business.",
"terms": "Terms and conditions apply.",
"shipping_charge": 0,
"adjustment": 0,
"adjustment_description": "Adjustment"
}