我正在尝试将消息与schema一起发布到主题。但是模式注册总是失败的。当我指定key\u schema值时，它无法注册
我收到以下错误消息：

{
"error_code": 50002,
"message": "Error registering JSON schema: {\"$schema\":\"http://json-schema.org/draft-04/schema#\",\"title\":\"Text Node\"}"
}

下面是有效载荷。我通过rest代理发送。

{"key_schema":"{\r\n  \"title\": \"String\",\r\n  \"type\": \"string\"\r\n}","value_schema":"{\r\n  \"title\": \"Transaction\",\r\n  \"type\": \"object\",\r\n  \"properties\": {\r\n    \"channelId\": {\r\n      \"type\": [\r\n        \"string\",\r\n        \"null\"\r\n      ]\r\n    },\r\n    \"Type\": {\r\n      \"type\": [\r\n        \"string\",\r\n        \"null\"\r\n      ]\r\n    },\r\n    \"transactionID\": {\r\n      \"type\": [\r\n        \"string\",\r\n        \"null\"\r\n      ]\r\n    },\r\n    \"paymentType\": {\r\n      \"type\": [\r\n        \"string\",\r\n        \"null\"\r\n      ]\r\n    }\r\n  },\r\n  \"required\": [\r\n    \"channelId\",\r\n    \"Type\",\r\n    \"transactionID\",\r\n    \"paymentType\"\r\n  ]\r\n}","records":[{"key":"123","value":{"channelId":"123","Type":"Cacnceled","transactionID":"123","paymentType":"PayPal"}}]}

如果没有密钥模式，我可以发布。
任何帮助都将不胜感激。