Problem stopping a build

When I attempt to stop a running build using the web admin I get the following exception. Is this something with the packaging of TeamServer that it's missing that class or a missing package on my end. I'm running Tomcat 5.5.15:

jetbrains.buildServer.xmlrpc.RemoteCallException: Call http://172.20.3.133:9090/RPC2 buildAgent.stopBuild: org.apache.xmlrpc.XmlRpcException: java.lang.Exception: java.lang.NoClassDefFoundError
at jetbrains.buildServer.xmlrpc.XmlRpcTargetImpl.call(XmlRpcTargetImpl.java:40)
at jetbrains.buildServer.serverSide.impl.XmlRpcClientBasedAgent.stopBuild(XmlRpcClientBasedAgent.java:110)
at jetbrains.buildServer.controllers.SimpleActionController$1.doProcess(SimpleActionController.java:34)
at jetbrains.buildServer.web.openapi.OneParamAction.process(OneParamAction.java:39)
at jetbrains.buildServer.controllers.BaseActionController.doAction(BaseActionController.java:31)
at jetbrains.buildServer.controllers.SimpleActionController.doHandle(SimpleActionController.java:90)
at jetbrains.buildServer.controllers.BuildServerController.handleRequestInternal(BuildServerController.java:32)
at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:139)
at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:44)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:684)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:625)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:392)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:347)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:667)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:595)
ERROR - de.impl.XmlRpcClientBasedAgent - jetbrains.buildServer.xmlrpc.RemoteCallException: Call http://172.20.3.133:9090/RPC2 buildAgent.stopBuild: jetbrains.buildServer.xmlrpc.RemoteCallException: Call http://172.20.3.133:9090/RPC2 buildAgent.stopBuild: org.apache.xmlrpc.XmlRpcException: java.lang.Exception: java.lang.NoClassDefFoundError
jetbrains.buildServer.xmlrpc.RemoteCallException: Call http://172.20.3.133:9090/RPC2 buildAgent.stopBuild: jetbrains.buildServer.xmlrpc.RemoteCallException: Call http://172.20.3.133:9090/RPC2 buildAgent.stopBuild: org.apache.xmlrpc.XmlRpcException: java.lang.Exception: java.lang.NoClassDefFoundError
at jetbrains.buildServer.xmlrpc.XmlRpcTargetImpl.call(XmlRpcTargetImpl.java:45)
at jetbrains.buildServer.serverSide.impl.XmlRpcClientBasedAgent.stopBuild(XmlRpcClientBasedAgent.java:110)
at jetbrains.buildServer.controllers.SimpleActionController$1.doProcess(SimpleActionController.java:34)
at jetbrains.buildServer.web.openapi.OneParamAction.process(OneParamAction.java:39)
at jetbrains.buildServer.controllers.BaseActionController.doAction(BaseActionController.java:31)
at jetbrains.buildServer.controllers.SimpleActionController.doHandle(SimpleActionController.java:90)
at jetbrains.buildServer.controllers.BuildServerController.handleRequestInternal(BuildServerController.java:32)
at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:139)
at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:44)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:684)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:625)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:392)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:347)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)