运行好端端的，一下子就访问不了了。

访问页面返回错误：

HTTP Status 500 – Internal Server Error
Type Status Report

Message Error occured when handling uri: /cat/r/t

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Apache Tomcat/8.5.41

后台错误日志：
Caused by: java.lang.NullPointerException
at com.dianping.cat.report.page.transaction.transform.AllMachineMerger.visitTransactionReport(AllMachineMerger.java:92)
at com.dianping.cat.report.page.transaction.transform.TransactionMergeHelper.mergeAllMachines(TransactionMergeHelper.java:34)
at com.dianping.cat.report.page.transaction.Handler.handleOutbound(Handler.java:238)
at sun.reflect.GeneratedMethodAccessor195.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.unidal.lookup.util.ReflectUtils.invokeMethod(ReflectUtils.java:49)
... 46 more