Error displaying Travel and Expenses Form

When trying to display a Travel and Expense form in EP 7 using the Display/Print button, I am getting an error. Adobe Forms works fine for other areas in ESS, but not this one. This can be run from SAP GUI with no issues, so it's just the Portal that is having the problem. Is this something where SAP_MSS is needed? Here's the error. Thanks!

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com.sap.tc.webdynpro.clientserver.adobe.pdfdocument.base.core.PDFDocumentRuntimeException: Failed to USEPDF

at com.sap.tc.webdynpro.clientserver.uielib.adobe.impl.InteractiveForm.afterHandleActionEvent(InteractiveForm.java:418)

at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.afterApplicationModification(ClientApplication.java:1132)

at com.sap.tc.webdynpro.clientserver.cal.ClientComponent.afterApplicationModification(ClientComponent.java:895)

at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.doRespond(WindowPhaseModel.java:573)

at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.processRequest(WindowPhaseModel.java:152)

at com.sap.tc.webdynpro.clientserver.window.WebDynproWindow.processRequest(WebDynproWindow.java:335)

at com.sap.tc.webdynpro.clientserver.cal.AbstractClient.executeTasks(AbstractClient.java:143)

at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doProcessing(ApplicationSession.java:313)

at com.sap.tc.webdynpro.clientserver.session.ClientSession.doApplicationProcessingPortal(ClientSession.java:733)

at com.sap.tc.webdynpro.clientserver.session.ClientSession.doApplicationProcessing(ClientSession.java:668)

at com.sap.tc.webdynpro.clientserver.session.ClientSession.doProcessing(ClientSession.java:250)

at com.sap.tc.webdynpro.clientserver.session.RequestManager.doProcessing(RequestManager.java:149)

at com.sap.tc.webdynpro.clientserver.session.core.ApplicationHandle.doProcessing(ApplicationHandle.java:73)

at com.sap.tc.webdynpro.portal.pb.impl.AbstractApplicationProxy.sendDataAndProcessActionInternal(AbstractApplicationProxy.java:860)

at com.sap.tc.webdynpro.portal.pb.impl.AbstractApplicationProxy.create(AbstractApplicationProxy.java:220)

at com.sap.portal.pb.PageBuilder.updateApplications(PageBuilder.java:1246)

at com.sap.portal.pb.PageBuilder.createPage(PageBuilder.java:354)

at com.sap.portal.pb.PageBuilder.init(PageBuilder.java:547)

at com.sap.portal.pb.PageBuilder.wdDoInit(PageBuilder.java:191)

at com.sap.portal.pb.wdp.InternalPageBuilder.wdDoInit(InternalPageBuilder.java:150)

at com.sap.tc.webdynpro.progmodel.generation.DelegatingComponent.doInit(DelegatingComponent.java:108)

at com.sap.tc.webdynpro.progmodel.controller.Controller.initController(Controller.java:215)

at com.sap.tc.webdynpro.progmodel.controller.Controller.init(Controller.java:200)

at com.sap.tc.webdynpro.clientserver.cal.ClientComponent.init(ClientComponent.java:430)

at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.init(ClientApplication.java:362)

at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.initApplication(ApplicationSession.java:748)

at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doProcessing(ApplicationSession.java:283)

at com.sap.tc.webdynpro.clientserver.session.ClientSession.doApplicationProcessingStandalone(ClientSession.java:713)

at com.sap.tc.webdynpro.clientserver.session.ClientSession.doApplicationProcessing(ClientSession.java:666)

at com.sap.tc.webdynpro.clientserver.session.ClientSession.doProcessing(ClientSession.java:250)

at com.sap.tc.webdynpro.clientserver.session.RequestManager.doProcessing(RequestManager.java:149)

at com.sap.tc.webdynpro.serverimpl.defaultimpl.DispatcherServlet.doContent(DispatcherServlet.java:62)

at com.sap.tc.webdynpro.serverimpl.defaultimpl.DispatcherServlet.doPost(DispatcherServlet.java:53)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)

at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.runServlet(HttpHandlerImpl.java:401)

at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.handleRequest(HttpHandlerImpl.java:266)

at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:387)

at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:365)

at com.sap.engine.services.httpserver.server.RequestAnalizer.invokeWebContainer(RequestAnalizer.java:944)

at com.sap.engine.services.httpserver.server.RequestAnalizer.handle(RequestAnalizer.java:266)

at com.sap.engine.services.httpserver.server.Client.handle(Client.java:95)

at com.sap.engine.services.httpserver.server.Processor.request(Processor.java:175)

at com.sap.engine.core.service630.context.cluster.session.ApplicationSessionMessageListener.process(ApplicationSessionMessageListener.java:33)

at com.sap.engine.core.cluster.impl6.session.MessageRunner.run(MessageRunner.java:41)

at com.sap.engine.core.thread.impl3.ActionObject.run(ActionObject.java:37)

at java.security.AccessController.doPrivileged(Native Method)

at com.sap.engine.core.thread.impl3.SingleThread.execute(SingleThread.java:100)

at com.sap.engine.core.thread.impl3.SingleThread.run(SingleThread.java:170)

Caused by: java.lang.NullPointerException

at com.sap.tc.webdynpro.clientserver.uielib.adobe.impl.AdobeFormHelper.checkAttributesOfElementChanged(AdobeFormHelper.java:335)

at com.sap.tc.webdynpro.clientserver.uielib.adobe.impl.AdobeFormHelper.isBoundContextChanged(AdobeFormHelper.java:280)

at com.sap.tc.webdynpro.clientserver.uielib.adobe.impl.InteractiveForm.afterHandleActionEvent(InteractiveForm.java:361)