Failure to react to misconfigured Apache Hadoop 2.6 clusters.

Yarn 2.6 adds two fields to YarnConfiguration: YarnConfiguration.YARN_APPLICATION_CLASSPATH and YarnConfiguration.DEFAULT_YARN_CROSS_PLATFORM_APPLICATION_CLASSPATH
We are checking for existence of these fields, but not whether they were consistent with each other. HDInsight is one example which misconfigures them.