Output file was found but is zero sized - Deleted [UNEXPECTED] [552457:RT37910837] java.lang.reflect.InvocationTargetException

 Error - 

Output type:   RTF

[6/16/21 6:35:58 AM] [552457:RT37904376] Output file was found but is zero sized - Deleted

[6/16/21 6:35:58 AM] [UNEXPECTED] [552457:RT37904376] java.lang.reflect.InvocationTargetException

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

        at java.lang.reflect.Method.invoke(Method.java:597)

[6/17/21 1:23:04 PM] [552457:RT37910806] Completed post-processing actions for request 37910806.

[6/17/21 1:31:28 PM] [OPPServiceThread0] Post-processing request 37910837.

[6/17/21 1:31:28 PM] [552457:RT37910837] Executing post-processing actions for request 37910837.

[6/17/21 1:31:28 PM] [552457:RT37910837] Starting XML Publisher post-processing action.

[6/17/21 1:31:28 PM] [552457:RT37910837]

Template code: XLAACCPB02

Template app:  XLA

Language:      en

Territory:     US

Output type:   RTF

[6/17/21 1:31:28 PM] [552457:RT37910837] Output file was found but is zero sized - Deleted

[6/17/21 1:31:28 PM] [UNEXPECTED] [552457:RT37910837] java.lang.reflect.InvocationTargetException

        at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

        at java.lang.reflect.Method.invoke(Method.java:597)

        at oracle.apps.xdo.common.xml.XSLT10gR1.invokeGetDocument(XSLT10gR1.java:746)

        at oracle.apps.xdo.common.xml.XSLT10gR1.transform(XSLT10gR1.java:449)

        at oracle.apps.xdo.common.xml.XSLT10gR1.transform(XSLT10gR1.java:258)

        at oracle.apps.xdo.common.xml.XSLTWrapper.transform(XSLTWrapper.java:182)

        at oracle.apps.xdo.template.fo.util.FOUtility.generateFO(FOUtility.java:1044)

        at oracle.apps.xdo.template.FOProcessor.generate(FOProcessor.java:941)

        at oracle.apps.xdo.oa.schema.server.TemplateHelper.runProcessTemplate(TemplateHelper.java:5978)

        at oracle.apps.xdo.oa.schema.server.TemplateHelper.processTemplate(TemplateHelper.java:3470)

        at oracle.apps.xdo.oa.schema.server.TemplateHelper.processTemplate(TemplateHelper.java:3559)

        at oracle.apps.fnd.cp.opp.XMLPublisherProcessor.process(XMLPublisherProcessor.java:311)

        at oracle.apps.fnd.cp.opp.OPPRequestThread.run(OPPRequestThread.java:176)

Caused by: java.lang.NullPointerException

        at oracle.xdo.parser.v2.FilePageManager.pageLength(FilePageManager.java:242)

        at oracle.xdo.comp.CXMLStream.seek(CXMLStream.java:199)

        at oracle.xdo.comp.CXMLStream.reset(CXMLStream.java:709)

        at oracle.xdo.parser.v2.DOMParser.getDocument(DOMParser.java:143)

        ... 17 more

[6/17/21 1:31:28 PM] [552457:RT37910837] Completed post-processing actions for request 37910837.

Solution - 

Temporary Directory pointing to /usr/tmp and no space available.

Changed the directory to different where ample of space available.