External table: exception while storing stats

create external table e3(a integer,b string,c double);
-- goes well
insert into e3 values(1,'2',3);
-- takes a while:
insert into e3 values(1,'2',3);
-- after 2 minutes
----------------------------------------------------------------------------------------------
ERROR : FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.StatsTask
INFO  : Completed executing command(queryId=hive_20180712120342_6893e234-44a0-4e48-8320-f1699557bae3); Time taken: 125.276 seconds
Error: Error while processing statement: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.StatsTask (state=08S01,code=1)

java.lang.ClassCastException: org.apache.hadoop.hive.metastore.api.LongColumnStatsData cannot be cast to org.apache.hadoop.hive.metastore.columnstats.cache.LongColumnStatsDataInspector
 at org.apache.hadoop.hive.metastore.columnstats.merge.LongColumnStatsMerger.merge(LongColumnStatsMerger.java:30) ~[hive-exec-3.1.0.3.0.0.0-1632.jar:3.1.0.3.0.0.0-1632]
 at org.apache.hadoop.hive.metastore.utils.MetaStoreUtils.mergeColStats(MetaStoreUtils.java:1084) ~[hive-exec-3.1.0.3.0.0.0-1632.jar:3.1.0.3.0.0.0-1632]
 at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.set_aggr_stats_for(HiveMetaStore.java:7514) ~[hive-exec-3.1.0.3.0.0.0-1632.jar:3.1.0.3.0.0.0-1632]
 at sun.reflect.GeneratedMethodAccessor80.invoke(Unknown Source) ~[?:?]
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_161]
 at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_161]
 at org.apache.hadoop.hive.metastore.RetryingHMSHandler.invokeInternal(RetryingHMSHandler.java:147) ~[hive-exec-3.1.0.3.0.0.0-1632.jar:3.1.0.3.0.0.0-1632]
 at org.apache.hadoop.hive.metastore.RetryingHMSHandler.invoke(RetryingHMSHandler.java:108) ~[hive-exec-3.1.0.3.0.0.0-1632.jar:3.1.0.3.0.0.0-1632]
 at com.sun.proxy.$Proxy34.set_aggr_stats_for(Unknown Source) ~[?:?]
 at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Processor$set_aggr_stats_for.getResult(ThriftHiveMetastore.java:17017) ~[hive-exec-3.1.0.3.0.0.0-1632.jar:3.1.0.3.0.0.0-1632]
 at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Processor$set_aggr_stats_for.getResult(ThriftHiveMetastore.java:17001) ~[hive-exec-3.1.0.3.0.0.0-1632.jar:3.1.0.3.0.0.0-1632]