RandomForest quits with ArrayIndexOutOfBoundsException while running sample

Hello,

when running the example under https://cwiki.apache.org/MAHOUT/partial-implementation.html with the recommended data sets several issues occur.
First: ARFF files seem no longer to be supported, I've been using the UCI format as recommended here (https://cwiki.apache.org/MAHOUT/breiman-example.html). Using ARFF files, Mahout quits when creating the description file (wrong number of attributes in the string), using UCI format it works.

The main error happends during the BuildForest step (I could not test TestForest, due to missing tree).
Running:
$MAHOUT_HOME/bin/mahout org.apache.mahout.classifier.df.mapreduce.BuildForest -Dmapred.max.split.size=1874231 -d convertedData/data.data -ds KDDTrain+.info -sl 5 -p -t 100 -o nsl-forest.

I tested different split.size values. 1874231, 187423, 18742 give the following error. 1874 does not finish on my machine (Dual Core MacBook Pro 2009, 8 Gb, SSD).

It quits after a while (map is almost done) with the following message:
11/12/17 16:23:24 INFO mapred.Task: Task 'attempt_local_0001_m_000998_0' done.
11/12/17 16:23:24 INFO mapred.Task: Task:attempt_local_0001_m_000999_0 is done. And is in the process of commiting
11/12/17 16:23:24 INFO mapred.LocalJobRunner:
11/12/17 16:23:24 INFO mapred.Task: Task attempt_local_0001_m_000999_0 is allowed to commit now
11/12/17 16:23:24 INFO output.FileOutputCommitter: Saved output of task 'attempt_local_0001_m_000999_0' to file:/Users/martin/Documents/Studium/Master/LargeScaleProcessing/Repository/mahout_algorithms_evaluation/testingRandomForests/nsl-forest
11/12/17 16:23:27 INFO mapred.LocalJobRunner:
11/12/17 16:23:27 INFO mapred.Task: Task 'attempt_local_0001_m_000999_0' done.
11/12/17 16:23:28 INFO mapred.JobClient: map 100% reduce 0%
11/12/17 16:23:28 INFO mapred.JobClient: Job complete: job_local_0001
11/12/17 16:23:28 INFO mapred.JobClient: Counters: 8
11/12/17 16:23:28 INFO mapred.JobClient: File Output Format Counters
11/12/17 16:23:28 INFO mapred.JobClient: Bytes Written=41869032
11/12/17 16:23:28 INFO mapred.JobClient: FileSystemCounters
11/12/17 16:23:28 INFO mapred.JobClient: FILE_BYTES_READ=37443033225
11/12/17 16:23:28 INFO mapred.JobClient: FILE_BYTES_WRITTEN=44946910704
11/12/17 16:23:28 INFO mapred.JobClient: File Input Format Counters
11/12/17 16:23:28 INFO mapred.JobClient: Bytes Read=20478569
11/12/17 16:23:28 INFO mapred.JobClient: Map-Reduce Framework
11/12/17 16:23:28 INFO mapred.JobClient: Map input records=125973
11/12/17 16:23:28 INFO mapred.JobClient: Spilled Records=0
11/12/17 16:23:28 INFO mapred.JobClient: Map output records=100000
11/12/17 16:23:28 INFO mapred.JobClient: SPLIT_RAW_BYTES=215000
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 100
at org.apache.mahout.classifier.df.mapreduce.partial.PartialBuilder.processOutput(PartialBuilder.java:126)
at org.apache.mahout.classifier.df.mapreduce.partial.PartialBuilder.parseOutput(PartialBuilder.java:89)
at org.apache.mahout.classifier.df.mapreduce.Builder.build(Builder.java:303)
at org.apache.mahout.classifier.df.mapreduce.BuildForest.buildForest(BuildForest.java:201)
at org.apache.mahout.classifier.df.mapreduce.BuildForest.run(BuildForest.java:163)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.mahout.classifier.df.mapreduce.BuildForest.main(BuildForest.java:225)
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.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68)
at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139)
at org.apache.mahout.driver.MahoutDriver.main(MahoutDriver.java:188)
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:156)

PS: I adjusted the class to .classifier.df. and removed -oop