Error: IllegalArgumentException when loading RTC plan or query

Symptom

In IBM Rational Team Concert (RTC) environment deploys on WebSphere Application Server (WAS), when using WebUI to load a plan or a work item query, or when attempting to export a work item from a query or a plan, the operation fails with java.lang.IllegalArgumentException.  Browser console output shows that the following call returns HTTP 400 Bad Request error: ccm/service/com.ibm.team.apt.internal.service.IPlanRestServices/getItems2.

Below is more details of the error capture from the browser console output:

- POST http://xxx.xx.com/ccm/service/com.ibm.team.apt.internal.service.rest.IPlanRestService/getItems2 400 (Bad Request) _6 {message: "Unable to load /ccm/web/dojo/../../service/com.ibm…rvice.rest.IPlanRestService/getItems2 status: 400", response: {…}, status: 400, responseText: "{"errorMessage":null,"errorClass":"java.lang.Illeg…ThreadPool$Worker","errorTraceLineNumber":1892}]}", xhr: XMLHttpRequest, …} log: false message: "Unable to load /ccm/web/dojo/../../service/com.ibm.team.apt.internal.service.rest.IPlanRestService/getItems2 status: 400" response: {url: "/ccm/web/dojo/../../service/com.ibm.team.apt.internal.service.rest.IPlanRestService/getItems2", options: TMP, getHeader: ƒ, xhr: XMLHttpRequest, status: 400, …} responseText: "{"errorMessage":null,"errorClass":"java.lang.Illeg" status: 400 xhr: XMLHttpRequest {onreadystatechange: null, readyState: 4, timeout: 0, withCredentials: false, upload: XMLHttpRequestUpload, …} stack: "Error: Unable to load /ccm/web/dojo/../../service/com.ibm.team.apt.internal.service.rest.IPlanRestService/getItems2 status: 400↵ at new _6 (http://xxx.xxx.com/ccm/web/_js/?include=A~&etag=C4Dw7c0ouzu_en_US&_proxyURL=%2Fccm&ss=NtVZV&locale=en-us:2489:14)↵ at _11._6 [as handleResponse] (http://xxx.xxx.com/ccm/web/_js/?include=A~&etag=C4Dw7c0ouzu_en_US&_proxyURL=%2Fccm&ss=NtVZV&locale=en-us:6187:4)↵ at XMLHttpRequest._13 (http://xxx.xxx.com/ccm/web/_js/?include=A~&etag=C4Dw7c0ouzu_en_US&_proxyURL=%2Fccm&ss=NtVZV&locale=en-us:6202:5)" __proto__: Error
 

Error loading additional items: java.lang.IllegalArgumentExceptionhide details
java.lang.IllegalArgumentException
com.ibm.wsspi.webcontainer.util.RequestUtils.parseQueryString(RequestUtils.java:218)
com.ibm.ws.webcontainer.servlet.RequestUtils.parsePostData(RequestUtils.java:358)
com.ibm.ws.webcontainer.srt.SRTServletRequest.parseParameters(SRTServletRequest.java:2342)
com.ibm.ws.webcontainer.srt.SRTServletRequest.getParameterMap(SRTServletRequest.java:2991)
javax.servlet.ServletRequestWrapper.getParameterMap(ServletRequestWrapper.java:149)
com.ibm.team.repository.common.transport.ParameterWrapperHandler.createParameterWrapperFromRequest(ParameterWrapperHandler.java:45)
com.ibm.team.repository.servlet.AbstractTeamServerServlet.getParameters(AbstractTeamServerServlet.java:1335)
com.ibm.team.repository.servlet.AbstractTeamServerServlet.doModelledRestService(AbstractTeamServerServlet.java:587)
com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleRequest2(AbstractTeamServerServlet.java:2597)
com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleRequest(AbstractTeamServerServlet.java:2388)
com.ibm.team.repository.servlet.AbstractTeamServerServlet.service(AbstractTeamServerServlet.java:1836)
javax.servlet.http.HttpServlet.service(HttpServlet.java:668)
org.eclipse.equinox.http.registry.internal.ServletManager$ServletWrapper.service(ServletManager.java:180)
org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:128)
org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:76)