The server encountered an internal error while attempting to Authenticate via QCC Rest API

On QC 11, after attempting  http://OurQualityCenter:8080/qcbin/rest/is-authenticated, I get the expected 401.

The next step is to do http://OurQualityCenter:8080/qcbin/rest/authentication-point/authenticate=Y.

This second browser attempt returns an http error 500. I noticed login_jsp.class seems to be missing.  Can anybody give me some clues as to what is going on here?

type Exception report

message

descriptionThe server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: Unable to compile class for JSP
	org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:593)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:312)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:322)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:249)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.hp.qc.web.restapi.RESTApiFilter.doFilter(RESTApiFilter.java:65)
	org.springframework.security.util.FilterChainProxy.doFilter(FilterChainProxy.java:169)
	org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
	org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
	com.mercury.optane.core.state.ServerStatusFilter.doFilter(ServerStatusFilter.java:33)
	org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

root cause

java.io.FileNotFoundException: no such file: C:\Documents and Settings\All Users\Application Data\HP\ALM\jboss\server\default\work\jboss.web\localhost\qcbin\org\apache\jsp\authentication_002dpoint\login_jsp.class
	org.apache.jasper.compiler.SmapUtil$SDEInstaller.<init>(SmapUtil.java:253)
	org.apache.jasper.compiler.SmapUtil$SDEInstaller.install(SmapUtil.java:241)
	org.apache.jasper.compiler.SmapUtil.installSmap(SmapUtil.java:165)
	org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:454)
	org.apache.jasper.compiler.Compiler.compile(Compiler.java:335)
	org.apache.jasper.compiler.Compiler.compile(Compiler.java:313)
	org.apache.jasper.compiler.Compiler.compile(Compiler.java:300)
	org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:585)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:312)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:322)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:249)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.hp.qc.web.restapi.RESTApiFilter.doFilter(RESTApiFilter.java:65)
	org.springframework.security.util.FilterChainProxy.doFilter(FilterChainProxy.java:169)
	org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
	org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
	com.mercury.optane.core.state.ServerStatusFilter.doFilter(ServerStatusFilter.java:33)
	org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)