anchor.diff:                 for (int j = 0; j < numMetaReplicas; j++) {
                    RegionInfo meta = RegionReplicaUtil.getRegionInfoForReplica(
                                            RegionInfoBuilder.FIRST_META_REGIONINFO, j);
  -                 ServerName metaLocation = MetaTableLocator.waitMetaRegionLocation(master.getZooKeeper(), j, 1);
  +                 //If a metaLocation is null, All of its info would be empty here to be displayed.
  +                 ServerName metaLocation = null;
  +                 try {
  +                   metaLocation = MetaTableLocator.waitMetaRegionLocation(master.getZooKeeper(), j, 1);
  +                 } catch (NotAllMetaRegionsOnlineException e) {
  +                   //Region in transition state here throw a NotAllMetaRegionsOnlineException causes
  +                   //the UI crash.
  +                 }
                    for (int i = 0; i < 1; i++) {
  +                   //If metaLocation is null, default value below would be displayed in UI.
                      String hostAndPort = "";
                      float locality = 0.0f;
                      float localityForSsd = 0.0f;
  
positive.code:               for (int j = 0; j < numMetaReplicas; j++) {
                  RegionInfo meta = RegionReplicaUtil.getRegionInfoForReplica(
                          RegionInfoBuilder.FIRST_META_REGIONINFO, j);
                  ServerName metaLocation = MetaTableLocator.waitMetaRegionLocation(master.getZooKeeper(), j, 1);
                  for (int i = 0; i < 1; i++) {
                    String hostAndPort = "";
                    String readReq = "N/A";
                    String writeReq = "N/A";
  
negative.code:   import="org.apache.hadoop.hbase.master.http.MetaBrowser"
    import="org.apache.hadoop.hbase.master.http.RegionReplicaInfo"
    import="org.apache.hadoop.hbase.quotas.QuotaSettingsFactory"
    import="org.apache.hadoop.hbase.quotas.QuotaTableUtil"
    import="org.apache.hadoop.hbase.NotAllMetaRegionsOnlineException" %>
  <%@ page import="org.apache.hadoop.hbase.quotas.SpaceQuotaSnapshot" %>
  <%@ page import="org.apache.hadoop.hbase.quotas.ThrottleSettings" %>
  <%@ page import="org.apache.hadoop.hbase.util.Bytes" %>
  