Failed to resolve connection parameter for JCo Destination

I just installed NW73; ran initial configuration successfully. Migrated a WDJ application to 7.3 that was developed in 7.0; also migrated Models to use ARFC3 model. Deployed WDJ application successfully to NW73 server. I've created RFC JCO destinations (TK_RFC_METADATA_DEST & TK_MODELDATA_DESK) using NWA-->Configuration-->Infrastructure-->Destination.

When I ran the application, getting the following error: [any help resolving this issue is appreciated]

com.sap.tc.webdynpro.services.exceptions.WDRuntimeException: Exception was thrown in preprocessing phase of application session 815d589d196e11e382e900000093f012. The causing exception is nested. RID=81544473196e11e3939200000093f012

at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doPreprocessing(ApplicationSession.java:661)

at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doProcessing(ApplicationSession.java:347)

at com.sap.tc.webdynpro.clientserver.session.RequestManager.doProcessing(RequestManager.java:325)

at com.sap.tc.webdynpro.serverimpl.core.AbstractDispatcherServlet.doContent(AbstractDispatcherServlet.java:87)

at com.sap.tc.webdynpro.serverimpl.wdc.DispatcherServlet.doContent(DispatcherServlet.java:89)

at com.sap.tc.webdynpro.serverimpl.core.AbstractDispatcherServlet.doGet(AbstractDispatcherServlet.java:55)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:734)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)

at com.sap.engine.services.servlets_jsp.server.Invokable.invoke(Invokable.java:152)

at com.sap.engine.services.servlets_jsp.server.Invokable.invoke(Invokable.java:38)

at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.runServlet(HttpHandlerImpl.java:453)

at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.handleRequest(HttpHandlerImpl.java:210)

at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:441)

at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:430)

at com.sap.engine.services.servlets_jsp.filters.DSRWebContainerFilter.process(DSRWebContainerFilter.java:38)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.servlets_jsp.filters.ServletSelector.process(ServletSelector.java:81)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.servlets_jsp.filters.ApplicationSelector.process(ApplicationSelector.java:276)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.httpserver.filters.WebContainerInvoker.process(WebContainerInvoker.java:81)

at com.sap.engine.services.httpserver.chain.HostFilter.process(HostFilter.java:9)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.httpserver.filters.ResponseLogWriter.process(ResponseLogWriter.java:60)

at com.sap.engine.services.httpserver.chain.HostFilter.process(HostFilter.java:9)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.httpserver.filters.DefineHostFilter.process(DefineHostFilter.java:27)

at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.httpserver.filters.MonitoringFilter.process(MonitoringFilter.java:29)

at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.httpserver.filters.SessionSizeFilter.process(SessionSizeFilter.java:26)

at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.httpserver.filters.MemoryStatisticFilter.process(MemoryStatisticFilter.java:57)

at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.httpserver.filters.DSRHttpFilter.process(DSRHttpFilter.java:43)

at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)

at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)

at com.sap.engine.services.httpserver.server.Processor.chainedRequest(Processor.java:462)

at com.sap.engine.services.httpserver.server.Processor$FCAProcessorThread.process(Processor.java:270)

at com.sap.engine.services.httpserver.server.rcm.RequestProcessorThread.run(RequestProcessorThread.java:56)

at com.sap.engine.core.thread.execution.Executable.run(Executable.java:122)

at com.sap.engine.core.thread.execution.Executable.run(Executable.java:101)

at com.sap.engine.core.thread.execution.CentralExecutor$SingleThread.run(CentralExecutor.java:328)

Caused by: com.sap.tc.webdynpro.progmodel.context.DictionaryException: TypeBroker failed to access SLD: Error while obtaining JCO connection.

at com.sap.tc.webdynpro.progmodel.context.DictionaryHandler.getScalarType(DictionaryHandler.java:378)

at com.sap.tc.webdynpro.progmodel.context.DictionaryHandler.getDataType(DictionaryHandler.java:126)

at com.sap.tc.webdynpro.progmodel.context.DataAttributeInfo.init(DataAttributeInfo.java:438)

at com.sap.tc.webdynpro.progmodel.context.NodeInfo.initUnmappedAttributes(NodeInfo.java:1002)

at com.sap.tc.webdynpro.progmodel.context.DataNodeInfo.doInit(DataNodeInfo.java:294)

at com.sap.tc.webdynpro.progmodel.context.NodeInfo.init(NodeInfo.java:974)

at com.sap.tc.webdynpro.progmodel.context.NodeInfo.init(NodeInfo.java:978)

at com.sap.tc.webdynpro.progmodel.context.Context.init(Context.java:67)

at com.sap.tc.webdynpro.progmodel.controller.Controller.init(Controller.java:205)

at com.sap.tc.webdynpro.progmodel.components.Component.getCustomControllerInternal(Component.java:668)

at com.sap.tc.webdynpro.progmodel.components.Component.manageExternalContextMappings(Component.java:305)

at com.sap.tc.webdynpro.progmodel.components.Component.initController(Component.java:265)

at com.sap.tc.webdynpro.progmodel.controller.Controller.init(Controller.java:206)

at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.init(ClientApplication.java:586)

at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.doPreprocessing(ClientApplication.java:1453)

at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doPreprocessing(ApplicationSession.java:658)

... 46 more

Caused by: com.sap.dictionary.runtime.DdException: TypeBroker failed to access SLD: Error while obtaining JCO connection.

at com.sap.tc.webdynpro.services.datatypes.core.DictionarySetup$1.fillSldConnection(DictionarySetup.java:51)

at com.sap.dictionary.runtime.ProviderFactory.internalResolveLogicalNameToJCODestination(ProviderFactory.java:437)

at com.sap.dictionary.runtime.ProviderFactory.resolveLogicalNameToJCODestination(ProviderFactory.java:361)

at com.sap.dictionary.runtime.ProviderFactory.internalGetProvider(ProviderFactory.java:198)

at com.sap.dictionary.runtime.ProviderFactory.getProvider(ProviderFactory.java:161)

at com.sap.dictionary.runtime.DdDictionaryPool.getProvider(DdDictionaryPool.java:96)

at com.sap.dictionary.runtime.DdDictionaryPool.makeDictionary(DdDictionaryPool.java:75)

at com.sap.dictionary.runtime.DdDictionaryPool.makeDictionary(DdDictionaryPool.java:63)

at com.sap.dictionary.runtime.DdBroker.getDataType(DdBroker.java:230)

at com.sap.tc.webdynpro.progmodel.context.DictionaryHandler.getScalarType(DictionaryHandler.java:370)

... 61 more

Caused by: com.sap.tc.webdynpro.services.sal.sl.api.WDSystemLandscapeException: Error while obtaining JCO connection.

at com.sap.tc.webdynpro.serverimpl.wdc.sl.SystemLandscapeFactory.getJCOClientConnectionUnMapped(SystemLandscapeFactory.java:153)

at com.sap.tc.webdynpro.serverimpl.wdc.sl.SystemLandscapeFactory.getJCOClientConnectionUnMapped(SystemLandscapeFactory.java:161)

at com.sap.tc.webdynpro.services.sal.sl.core.SystemLandscapeInternal.getJCOClientConnectionUnMapped(SystemLandscapeInternal.java:64)

at com.sap.tc.webdynpro.services.datatypes.core.DictionarySetup$1.fillSldConnection(DictionarySetup.java:32)

... 70 more

Caused by: com.sap.tc.webdynpro.services.exceptions.WDRuntimeException: Failed to resolve connection parameter for 'TK_RFC_METADATA_DEST'

at com.sap.tc.webdynpro.serverimpl.wdc.sl.JCOClientConnection.resolveConnectionParameter4MsgServerJCODestination(JCOClientConnection.java:603)

at com.sap.tc.webdynpro.serverimpl.wdc.sl.JCOClientConnection.resolveConnectionParameter(JCOClientConnection.java:428)

at com.sap.tc.webdynpro.serverimpl.core.sl.AbstractJCOClientConnection.init(AbstractJCOClientConnection.java:237)

at com.sap.tc.webdynpro.serverimpl.core.sl.AbstractJCOClientConnection.<init>(AbstractJCOClientConnection.java:222)

at com.sap.tc.webdynpro.serverimpl.wdc.sl.JCOClientConnection.<init>(JCOClientConnection.java:84)

at com.sap.tc.webdynpro.serverimpl.wdc.sl.SystemLandscapeFactory.getJCOClientConnectionUnMapped(SystemLandscapeFactory.java:151)

... 73 more

Caused by: java.lang.NullPointerException: while trying to invoke the method java.lang.String.equals(java.lang.Object) of an object loaded from field com.sap.tc.webdynpro.serverimpl.wdc.sl.JCOClientConnection.userDefinition of an object loaded from local variable 'this'

at com.sap.tc.webdynpro.serverimpl.wdc.sl.JCOClientConnection.resolveConnectionParameter4MsgServerJCODestination(JCOClientConnection.java:532)

... 78 more