IOException thrown when uploading the attached file (WordML)

Also when saving from LE (in fact updating the file)

17:37:50,776 INFO [CompassBackendSession] Saving all queued resources. size=1
17:37:50,891 ERROR [AbstractTransformer] An error occured while trying to perform a transformation chain.
java.io.IOException: Invalid header signature; read 7311066695147732796, expected -2226271756974174256
at org.apache.poi.poifs.storage.HeaderBlockReader.<init>(HeaderBlockReader.java:91)
at org.apache.poi.poifs.filesystem.POIFSFileSystem.<init>(POIFSFileSystem.java:83)
at org.apache.poi.hwpf.HWPFDocument.verifyAndBuildPOIFS(HWPFDocument.java:119)
at org.apache.poi.hwpf.extractor.WordExtractor.<init>(WordExtractor.java:32)
at org.nuxeo.ecm.platform.transform.plugin.poi.WordToTextPlugin.transform(WordToTextPlugin.java:71)
at org.nuxeo.ecm.platform.transform.transformer.AbstractTransformer.transform(AbstractTransformer.java:174)
at org.nuxeo.ecm.platform.transform.service.TransformService.transform(TransformService.java:157)
at org.nuxeo.ecm.platform.transform.service.TransformService.transform(TransformService.java:174)
at org.nuxeo.ecm.core.search.blobs.NXTransformBlobExtractor.extract(NXTransformBlobExtractor.java:84)
at org.nuxeo.ecm.core.search.api.backend.indexing.resources.factory.ResolvedResourcesFactory.blobToText(ResolvedResourcesFactory.java:267)
at org.nuxeo.ecm.core.search.api.backend.indexing.resources.factory.ResolvedResourcesFactory.convertForFullText(ResolvedResourcesFactory.java:233)
at org.nuxeo.ecm.core.search.api.backend.indexing.resources.factory.ResolvedResourcesFactory.extractForFullText(ResolvedResourcesFactory.java:170)
at org.nuxeo.ecm.core.search.api.backend.indexing.resources.factory.ResolvedResourcesFactory.computeFulltext(ResolvedResourcesFactory.java:120)
at org.nuxeo.ecm.core.search.api.backend.indexing.resources.factory.ResolvedResourcesFactory.computeAggregatedResolvedResourcesFrom(ResolvedResourcesFactory.java:289)
at org.nuxeo.ecm.core.search.service.SearchServiceImpl.index(SearchServiceImpl.java:263)
at org.nuxeo.ecm.core.search.threading.IndexingTask.run(IndexingTask.java:72)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
at java.lang.Thread.run(Thread.java:595)