Subida de archivos fallida - file upload failed.

[frguer...@metabiblioteca.com]

Hola, alguien conoce la causa del siguiente error: 2018-08-06 14:35:44,194 WARN  org.dspace.app.webui.servlet.DSpaceServlet @ sop...@metabiblioteca.com:session_id=07C53C7F776068762993B0FAC96D25FC:ip_addr=190.159.7.172:general_jspui_error:java.lang.NullPointerException - Está ocurriendo al intentar subir un archivo, ya sea un logo de una comunidad o colección, o un documento de un ítem, adjunto el stack trace de del mismo, ya revisé los archivos dspace.cfg y bitstore.xml y en ninguna parte me dice algo sobre el almacenamiento temporal de archivos cargados, solo el maximo de carga, los permisos de las carpetas estan correctamente configurados (chmod 765) y el propietario es el usuario tomcat7, ¿que mas puedo hacer para encontrar la causa? gracias por la ayuda comunidad.

Hello, someone knows the cause of the following error: 2018-08-06 14:35:44,194 WARN  org.dspace.app.webui.servlet.DSpaceServlet @ sop...@metabiblioteca.com:session_id=07C53C7F776068762993B0FAC96D25FC:ip_addr=190.159.7.172:general_jspui_error:java.lang.NullPointerException - It is happening when trying to upload a file, either a logo of a community or collection, or a document of an item, attached the stack trace of it, and I checked the files dspace.cfg and bitstore.xml and nowhere does it tell me something about the temporary storage of uploaded files, only the maximum load, the permissions of the folders are correctly configured (chmod 765) and the owner is the user tomcat7, what else can I do to find the cause?
thanks for the help community

Stack trace:

2018-08-06 14:35:44,194 WARN  org.dspace.app.webui.servlet.DSpaceServlet @ sop...@metabiblioteca.com:session_id=07C53C7F776068762993B0FAC96D25FC:ip_addr=190.159.7.172:general_jspui_error:java.lang.NullPointerException
java.lang.NullPointerException
    at org.dspace.storage.bitstore.BitstreamStorageServiceImpl.store(BitstreamStorageServiceImpl.java:107)
    at org.dspace.content.BitstreamServiceImpl.create(BitstreamServiceImpl.java:101)
    at org.dspace.content.BitstreamServiceImpl.create(BitstreamServiceImpl.java:120)
    at org.dspace.content.ItemServiceImpl.createSingleBitstream(ItemServiceImpl.java:331)
    at org.dspace.submit.step.UploadStep.processUploadFile(UploadStep.java:545)
    at org.dspace.app.webui.servlet.SubmissionController.doDSPost(SubmissionController.java:314)
    at org.dspace.app.webui.servlet.DSpaceServlet.processRequest(DSpaceServlet.java:122)
    at org.dspace.app.webui.servlet.DSpaceServlet.doPost(DSpaceServlet.java:80)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.dspace.app.webui.filter.RegisteredOnlyFilter.doFilter(RegisteredOnlyFilter.java:66)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.dspace.utils.servlet.DSpaceWebappServletFilter.doFilter(DSpaceWebappServletFilter.java:78)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:221)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
    at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:190)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)