Mahout usage IncompatibleClassChangeError Exception

The error pops up while using mahout collab filtering on Hadoop 2. Exception in thread “main” java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.JobContext, but class was expected at org.apache.mahout.common.HadoopUtil.getCustomJobName(HadoopUtil.java:174) at org.apache.mahout.common.AbstractJob.prepareJob(AbstractJob.java:614) at org.apache.mahout.cf.taste.hadoop.preparation.PreparePreferenceMatrixJob.run(PreparePreferenceMatrixJob.java:73) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70) at org.apache.mahout.cf.taste.hadoop.item.RecommenderJob.run(RecommenderJob.java:168) at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70) at org.apache.mahout.cf.taste.hadoop.item.RecommenderJob.main(RecommenderJob.java:335) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.hadoop.util.RunJar.main(RunJar.java:208)   Fix: Specify hadoop 2 version …

More