Error creating JCO connection: java.lang.NullPointerException

Symptom

When creating or viewing a Jco connection in the Web Dynpro Content Administrator it fails with a similar error to the following:

Error as seen in the defaultTrace:

• Exception occured during processing of Web Dynpro application sap.com/tc~wd~tools/Explorer. The causing exception is nested.
  [EXCEPTION]
   java.lang.NullPointerException
  at com.sap.tc.webdynpro.serverimpl.wdc.sl.SystemLandscapeFactory.checkStatus(SystemLandscapeFactory.java:991)
  at com.sap.tc.webdynpro.services.sal.sl.api.WDSystemLandscape.checkStatus(WDSystemLandscape.java:485)
  at com.sap.tc.webdynpro.tools.sld.NameDefinition.updateJCODestinations(NameDefinition.java:286)
  at com.sap.tc.webdynpro.tools.sld.NameDefinition.updateNavigation(NameDefinition.java:251)
  at com.sap.tc.webdynpro.tools.sld.NameDefinition.wdDoInit(NameDefinition.java:158)
  at com.sap.tc.webdynpro.tools.sld.wdp.InternalNameDefinition.wdDoInit(InternalNameDefinition.java:236)
  .............

Environment

SAP J2EE Engine 640

SAP J2EE Engine 700

Reproducing the Issue

Create or modify a JCo connection using the Web Dynpro Content Administrator.

Cause

The cause of the issue is that the JCO connections have been created directly using the SLD WebUI. When they are created this way certain other internal actions won't be executed which is the task of the Web Dynpro Content Administrator.

Resolution

To solve the issue you have to delete the jco connections in the SLD then only use the Web Dynpro Content Administrator to create and maintain connections.

1. Invoke the SLD WebUI: http://:/sld
      > Administration
      > Content Maintenance  
      > choose here 'JCO Message Server Destination (X)'
2. Here delete the entries.
3. Then you should be able to successfully create JCo connections in the Web Dynpro Content Administrator.