If the output classes are more than 18 we see an error

If the output classes are more than 18 we see an error:

A fatal error has been detected by the Java Runtime Environment:
 EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ffe2390440b, pid=6024, tid=0x00000000000043e8 JRE version: Java(TM) SE Runtime Environment (8.0_201-b09) (build 1.8.0_201-b09) Java VM: Java HotSpot(TM) 64-Bit Server VM (25.201-b09 mixed mode windows-amd64 compressed oops)
Problematic frame:
 C  [msvcrt.dll+0x7440b]
Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
 An error report file with more information is saved as:
 D:\DeepLerning4j\dl4j-examples-master\hs_err_pid6024.log

 If you would like to submit a bug report, please visit:
   http://bugreport.java.com/bugreport/crash.jsp
 The crash happened outside the Java Virtual Machine in native code.
 See problematic frame for where to report the bug.

How can I fix it?

File trainData = new File(DATA_PATH.toString());
FileSplit train = new FileSplit(trainData, NativeImageLoader.ALLOWED_FORMATS, randNumGen);
ParentPathLabelGenerator labelMaker = new ParentPathLabelGenerator();
ImageRecordReader recordReader = new ImageRecordReader(height, width, channels, labelMaker);   
recordReader.initialize(train);             
DataSetIterator dataIter = new RecordReaderDataSetIterator(recordReader, batchSize, 1, outputNum);