Hi @Yingding_Wang,
Was the 3.0.1 connector deployed to all Spark Executors? I think that this error is due to the change in the MongoSpark object as part of the 3.0.1 release.
The different serialVersionUID indicates mixing two versions of the MongoDB Spark Connector. Please ensure that both the MongoDB Spark Connectors are all of the same version and all Spark versions are the same.
All the best,
Ross