GATK4 SplitNCigarReads RuntimeIOException: Attempt to add record to closed writer.

On a Linux cluster, I ran this command on a node (no job scheduler):

./gatk SplitNCigarReads -R /bigdisk/databases/genomes/human/Homo_sapiens.GRCh37.75.dna.primary_assembly.fa -I 28_tumor.dedupped.bam -O 28_tumor.split.bam

I get this error during SplitN's second pass:

13:27:28.945 INFO  ProgressMeter -           4:74283282            163.1             288256000        1767147.3`
13:27:38.955 INFO  ProgressMeter -           4:74283830            163.3             288523000        1766976.9`
13:27:46.176 INFO  SplitNCigarReads - Shutting down engine`
[February 6, 2018 1:27:46 PM CET] org.broadinstitute.hellbender.tools.walkers.rnaseq.SplitNCigarReads done. Elapsed time: 163.42 minutes.`
Runtime.totalMemory()=12006719488`
htsjdk.samtools.util.RuntimeIOException: Attempt to add record to closed writer.
    at htsjdk.samtools.util.AbstractAsyncWriter.write(AbstractAsyncWriter.java:57)
    at htsjdk.samtools.AsyncSAMFileWriter.addAlignment(AsyncSAMFileWriter.java:53)
    at org.broadinstitute.hellbender.utils.read.SAMFileGATKReadWriter.addRead(SAMFileGATKReadWriter.java:21)
    at org.broadinstitute.hellbender.tools.walkers.rnaseq.OverhangFixingManager.writeReads(OverhangFixingManager.java:349)
    at org.broadinstitute.hellbender.tools.walkers.rnaseq.OverhangFixingManager.flush(OverhangFixingManager.java:329)
    at org.broadinstitute.hellbender.tools.walkers.rnaseq.SplitNCigarReads.closeTool(SplitNCigarReads.java:195)
    at org.broadinstitute.hellbender.engine.GATKTool.doWork(GATKTool.java:897)
    at org.broadinstitute.hellbender.cmdline.CommandLineProgram.runTool(CommandLineProgram.java:136)
    at org.broadinstitute.hellbender.cmdline.CommandLineProgram.instanceMainPostParseArgs(CommandLineProgram.java:179)
    at org.broadinstitute.hellbender.cmdline.CommandLineProgram.instanceMain(CommandLineProgram.java:198)
    at org.broadinstitute.hellbender.Main.runCommandLineProgram(Main.java:152)
    at org.broadinstitute.hellbender.Main.mainEntry(Main.java:195)
    at org.broadinstitute.hellbender.Main.main(Main.java:275)

The output file 28_tumor.split.bam is 0 bytes, and ther is an index file, 0 bytes also.

Java version: 1.8.0_162
GATK version: 4.0.0.0
OS: CentOS release 6.8

I ran this command on a different computer with Ubuntu 16.04 and had no problems. On different BAM files I get the same error. Any ideas? It's frustrating that I can't get GATK to run efficentlyon the cluster, only on slow computers or with computers with limited disk space. It took a month to run on about 45 pairs of RNA-Seq samples (of course I made errors during the time), so I really need it to run on the cluster.

Thanks,
Zsuzsa