我在BIRT报表设计器上设计了报表设计文件（test_report.rptdesign）。我可以通过单击BIRT报表设计器上的“在web查看器中查看报表”来查看报表。但是，当我尝试使用TOMCAT查看报表时，出现“没有可用的报表设计对象“错误。TOMCAT和“BIRT VIEWER”配置正确。我将“BIRT VIEWER”文件放在“C：\xampp\tomcat\webapps”文件夹下。并且我正确配置了“\birt-viewer\WEB-INF\web.xml”文件。我在TOMCAT服务器上尝试了示例报表（customers.rptdesign、TopNPercent.rptdesign），它工作正常。但是，当我尝试使用PostgreSQL时，它不工作，出现异常。我
错误消息如下所示：

There is no report design object available.

org.eclipse.birt.report.exception.ViewerException: There is no report design object available.
at org.eclipse.birt.report.context.ViewerAttributeBean.__init(ViewerAttributeBean.java:230)
at org.eclipse.birt.report.context.BaseAttributeBean.init(BaseAttributeBean.java:233)
at org.eclipse.birt.report.context.ViewerAttributeBean.(ViewerAttributeBean.java:113)
at org.eclipse.birt.report.context.BirtContext.__init(BirtContext.java:44)
at org.eclipse.birt.report.context.BaseContext.(BaseContext.java:69)
at org.eclipse.birt.report.context.BirtContext.(BirtContext.java:30)
at org.eclipse.birt.report.servlet.ViewerServlet.__getContext(ViewerServlet.java:150)
at org.eclipse.birt.report.servlet.BirtSoapMessageDispatcherServlet.doPost(BirtSoapMessageDispatcherServlet.java:204)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at org.apache.axis.transport.http.AxisServletBase.service(AxisServletBase.java:327)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.eclipse.birt.report.servlet.BirtSoapMessageDispatcherServlet.service(BirtSoapMessageDispatcherServlet.java:112)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.eclipse.birt.report.filter.ViewerFilter.doFilter(ViewerFilter.java:68)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)

谢谢你的好意。