UnsupportedOperationException in BasicDeserializer?

Hi,

I was wondering if anyone can help me out with this exception that I'm
getting from Hessian? What does it mean? Why does it occur? How can I
debug it further?

Thanks for your help!

Charles

2005-11-15 12:17:13,437 [http-80-Processor23] ERROR
com.luntsys.luntbuild.services.HessianService - Exception catched in
HessianService.service()
java.lang.UnsupportedOperationException:
com.caucho.hessian.io.BasicDeserializer@xxx
    at com.caucho.hessian.io.Deserializer.readMap(Deserializer.java:79)
    at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:999)
    at
com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:134)
    at
com.luntsys.luntbuild.services.HessianService.service(HessianService.java:66)
    at
org.apache.tapestry.engine.AbstractEngine.service(AbstractEngine.java:837)
    at
org.apache.tapestry.ApplicationServlet.doService(ApplicationServlet.java:197)
    at
org.apache.tapestry.ApplicationServlet.doPost(ApplicationServlet.java:326)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
    at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
    at
net.sf.acegisecurity.intercept.web.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:70)
    at
net.sf.acegisecurity.intercept.web.SecurityEnforcementFilter.doFilter(SecurityEnforcementFilter.java:169)
    at
net.sf.acegisecurity.util.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:105)
    at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
    at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
    at
net.sf.acegisecurity.ui.AbstractIntegrationFilter.doFilter(AbstractIntegrationFilter.java:170)
    at
net.sf.acegisecurity.util.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:105)
Received on Mon 14 Nov 2005 17:51:34 -0800