21:23:48,851 ERROR [org.modeshape.jcr.SequencingRunner] (modeshape-sequencer-8-thread-3) The 'msoffice-sequencer' sequencer of repositor
y 'XXX' had an error while processing '/doc123.xls/jcr:content/jcr:data' in workspace 'default' and generating output '/derived/doc123.xls': java.lang.NullPointerException
        at org.modeshape.sequencer.msoffice.excel.ExcelMetadataReader.instance(ExcelMetadataReader.java:81)
        at org.modeshape.sequencer.msoffice.MSOfficeMetadataSequencer.sequenceExcel(MSOfficeMetadataSequencer.java:197)
        at org.modeshape.sequencer.msoffice.MSOfficeMetadataSequencer.execute(MSOfficeMetadataSequencer.java:175)
        at org.modeshape.jcr.SequencingRunner.run(SequencingRunner.java:224)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_21]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_21]
        at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_21]