Druid 0.18.1 upgrade , real-time data not getting processed

Hi,

I am facing an issue with real-time data not being processed but throwing the following error

2020-07-12T17:53:13,976 INFO [task-runner-0-priority-0] org.apache.druid.indexing.seekablestream.SeekableStreamIndexTaskRunner - Row at partition[0] offset[4034741773] was unparseable.
2020-07-12T17:53:13,976 INFO [task-runner-0-priority-0] org.apache.druid.indexing.seekablestream.SeekableStreamIndexTaskRunner - Row at partition[0] offset[4034741773] was unparseable.

The same message gets processed in 0.16.0-incubating version.

The KAFKA version is 2.0.0 and no changes in the environment except druid binaries.

JsonReader.java

@Override
public List parseInputRows(String line) throws IOException, ParseException
{
final JsonNode document = mapper.readValue(line, JsonNode.class); // this is the line which throws exception
final Map<String, Object> flattened = flattener.flatten(document);
return Collections.singletonList(MapInputRowParser.parse(getInputRowSchema(), flattened));
}

Here is the exception i get when i enabled logParseExceptions in my spec.

org.apache.druid.java.util.common.parsers.ParseException: Unable to parse row [{]

at org.apache.druid.data.input.IntermediateRowParsingReader$1.hasNext(IntermediateRowParsingReader.java:67) ~[druid-core-0.18.1.jar:0.18.1]

at org.apache.druid.java.util.common.parsers.CloseableIterator$1.hasNext(CloseableIterator.java:43) ~[druid-core-0.18.1.jar:0.18.1]

Could any please look into this issue