2676404 - Message Monitor Overview does not show anything

When accessing the Message Monitor in the NWA, the Message Monitor Overview does not show anything, also, the drop-down menus do not show any values.

If you click in the Refresh button, an HTTP 500 Internal Server Error occurs, and the following exception is visible in the Log Viewer Developer Traces:

500 Internal Server Error is returned for HTTP request [http://<IP>:<host>/webdynpro/resources/sap.com/tc~lm~itsam~ui~mainframe~wd/FloorPlanApp]:
  component [dispatcher],
  web module [webdynpro/resources/sap.com/tc~lm~itsam~ui~mainframe~wd],
  application [sap.com/tc~lm~itsam~ui~mainframe~wd],
  DC name [sap.com/tc~lm~itsam~ui~mainframe~wd],
  CSN component[BC-NWA-INC-UIF],
  problem categorization [],
  internal categorization [XXXXXXX].

[EXCEPTION]
java.lang.NullPointerException: while trying to invoke the method com.sap.tc.lm.itsam.co.ui.xi.msg.ximessagedetailed.wdp.IPrivateMessageOverviewView$ITimeIntervalsElement.getUiPeriod() of a null object returned from com.sap.tc.lm.itsam.co.ui.xi.msg.ximessagedetailed.wdp.IPrivateMessageOverviewView$IContextNode.currentTimeIntervalsElement()
at com.sap.tc.lm.itsam.co.ui.xi.msg.ximessagedetailed.MessageOverviewView.onActionRefresh(MessageOverviewView.java:470)
at com.sap.tc.lm.itsam.co.ui.xi.msg.ximessagedetailed.wdp.InternalMessageOverviewView.wdInvokeEventHandler(InternalMessageOverviewView.java:356)
at com.sap.tc.webdynpro.progmodel.generation.DelegatingView.invokeEventHandler(DelegatingView.java:142)
at com.sap.tc.webdynpro.progmodel.controller.Action.fire(Action.java:75)
at com.sap.tc.webdynpro.clientserver.phases.ProcessingEventPhase.doHandleActionEvent(ProcessingEventPhase.java:159)

If you scroll down in the Log Viewer Developer Traces, you will also see entries like:

Creating the XILandscpae failed; Reason: com.sap.aii.rwb.exceptions.BuildLandscapeException: No System Landscape Directory registered
[EXCEPTION]
com.sap.aii.rwb.exceptions.BuildLandscapeException: No System Landscape Directory registered
at com.sap.aii.rwb.agent.server.SLDAgentBean.buildSLD(SLDAgentBean.java:772)
at com.sap.aii.rwb.agent.server.SLDAgentBean.provideSld(SLDAgentBean.java:264)

or

Caused by: com.sap.aii.utilxi.sld.XISldException: Received response is not a CIM Operation Response! Check "http://<host>:<port>/sld/cimom/" is the correct URL for the SLD CIM Object Manager (default is "http://<host>:<port>/sld/cimom") and that user "XXXXX" has access to the SLD via http and is not required to change his/her password.
at com.sap.aii.utilxi.sld.MRSldProxy.loadComponents(MRSldProxy.java:1183)

• SAP NetWeaver
• SAP Process Integration

Monitor, Message, Overview, Blank, Empty, Nothing, Error, SLD, User, Loads, Dropdown, Drop down, Process Integration, PI, Process Orchestration, PO, NetWeaver, XI, AEX, sap.com/tc~lm~itsam~co~ui~xi~msg~wd, tc~lm~itsam~co~ui~xi~msg~wd, sap.com, itsam, tclm, tclmitsamcouiximsgwd , KBA , BC-NWA-XPI , Process Integration (PI) Monitoring , BC-NWA-INC-UIF , UI Framework , Problem