# Spark libraries conflict with Hadoop libraries

In some cases, library versions contained in JARs from PDI, Spark, Hadoop, AEL, and/or Kettle plugins may conflict with one another, causing general problems where Spark libraries conflict with Hadoop libraries and potentially creating AEL-specific problems. To read more about this issue, including how to address it, see the article [AEL and Spark Library Conflicts](https://pentaho-public.atlassian.net/wiki/spaces/COM/pages/222003239/AEL+and+Spark+Library+Conflicts) on the Pentaho Community Wiki.