DataException, null used for required field of type string

org.apache.kafka.connect.errors.ConnectException: Invalid default value 
at io.debezium.connector.mysql.AbstractReader.wrap(AbstractReader.java:230) 
at io.debezium.connector.mysql.AbstractReader.failed(AbstractReader.java:208) 
at io.debezium.connector.mysql.BinlogReader.handleEvent(BinlogReader.java:508) 
at com.github.shyiko.mysql.binlog.BinaryLogClient.notifyEventListeners(BinaryLogClient.java:1095) 
at com.github.shyiko.mysql.binlog.BinaryLogClient.listenForEventPackets(BinaryLogClient.java:943) 
at com.github.shyiko.mysql.binlog.BinaryLogClient.connect(BinaryLogClient.java:580) 
at com.github.shyiko.mysql.binlog.BinaryLogClient$7.run(BinaryLogClient.java:825) 
at java.lang.Thread.run(Thread.java:748) Caused by: org.apache.kafka.connect.errors.SchemaBuilderException: Invalid default value 
at org.apache.kafka.connect.data.SchemaBuilder.defaultValue(SchemaBuilder.java:131) 
at io.debezium.relational.TableSchemaBuilder.addField(TableSchemaBuilder.java:346) 
at io.debezium.relational.TableSchemaBuilder.lambda$create$0(TableSchemaBuilder.java:106) 
at java.util.ArrayList.forEach(ArrayList.java:1257) 
at java.util.Collections$UnmodifiableCollection.forEach(Collections.java:1080) 
at java.util.Collections$UnmodifiableCollection.forEach(Collections.java:1080) 
at io.debezium.relational.TableSchemaBuilder.create(TableSchemaBuilder.java:97) 
at io.debezium.relational.RelationalDatabaseSchema.buildAndRegisterSchema(RelationalDatabaseSchema.java:117) 
at io.debezium.connector.mysql.MySqlSchema.lambda$applyDdl$4(MySqlSchema.java:374) 
at java.lang.Iterable.forEach(Iterable.java:75) 
at io.debezium.connector.mysql.MySqlSchema.applyDdl(MySqlSchema.java:368) 
at io.debezium.connector.mysql.BinlogReader.handleQueryEvent(BinlogReader.java:694) 
at io.debezium.connector.mysql.BinlogReader.handleEvent(BinlogReader.java:492) ... 5 more 
Caused by: org.apache.kafka.connect.errors.DataException: Invalid value: null used for required field: "null", schema type: STRING 
at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:220) 
at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:213) 
at org.apache.kafka.connect.data.SchemaBuilder.defaultValue(SchemaBuilder.java:129) ... 17 more