Are you using Data Visualizer ML feature?
If so, I suggest reading the blog post about importing CSV, you might find an example or how to fix it for your case.
If not, please add more information about stack version and steps you are doing.
Apache, Apache Lucene, Apache Hadoop, Hadoop, HDFS and the yellow elephant
logo are trademarks of the
Apache Software Foundation
in the United States and/or other countries.