Apache Avro SchemaParseException：非法初始字符问题求助

配置应用Sink时遇到Avro解析错误，解析模式触发SchemaParseException，提示非法初始字符。异常栈信息如下：

Exception in thread "lakehouse-io-1-1" org.apache.avro.SchemaParseException: Illegal initial character: {"type":"record","name":"blah_schema","fields":[{"name":"blah_string","type":"string"},{"name":"blah_int","type":"int"}]}
        at org.apache.avro.Schema.validateName(Schema.java:1562)
        at org.apache.avro.Schema.access$400(Schema.java:91)
        at org.apache.avro.Schema$Name.<init>(Schema.java:701)
        at org.apache.avro.Schema$Names.get(Schema.java:1528)
        at org.apache.avro.Schema.parse(Schema.java:1636)
        at org.apache.avro.Schema$Parser.parse(Schema.java:1430)
        at org.apache.avro.Schema$Parser.parse(Schema.java:1418)
        at org.apache.pulsar.ecosystem.io.lakehouse.sink.SinkWriter.parseRecordSchema(SinkWriter.java:124)
        at org.apache.pulsar.ecosystem.io.lakehouse.sink.SinkWriter.run(SinkWriter.java:203)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
        at java.base/java.lang.Thread.run(Thread.java:833)

使用的模式如下：

{"type":"record","name":"blah_schema","fields":[{"name":"blah_string","type":"string"},{"name":"blah_int","type":"int"}]}

该模式符合Avro命名规范，已检查周围字符和编码，未发现异常，但错误仍存在。希望了解错误原因及解决方法，或得到相关问题的排查建议。

已尝试的解决方法：

• 测试不同模式：尝试多种类似格式的模式，问题均存在
• 验证编码：确认模式文件为UTF-8编码，符合Avro要求
• 确认模式准确性：确保传递给解析器的模式与定义完全一致，未被修改

尽管做了以上尝试，问题仍未解决，希望获得更多排查方向。

内容的提问来源于stack exchange，提问作者wkargul