diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 45ca470ce69bda06484feea2af2a9dec004e815f..b57cc559c331b66bfb185e5754a6b4c12753db3e 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -613,7 +613,7 @@ static int32_t tscEstimateQueryMsgSize(SSqlObj *pSql, int32_t clauseIndex) {
          tableSerialize + sqlLen + 4096 + pQueryInfo->bufLen;
 }
 
-static char *doSerializeTableInfo(SQueryTableMsg* pQueryMsg, SSqlObj *pSql, char *pMsg) {
+static char *doSerializeTableInfo(SQueryTableMsg* pQueryMsg, SSqlObj *pSql, char *pMsg, int32_t *succeed) {
   STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(&pSql->cmd, pSql->cmd.clauseIndex, 0);
   TSKEY dfltKey = htobe64(pQueryMsg->window.skey);
 
@@ -626,9 +626,14 @@ static char *doSerializeTableInfo(SQueryTableMsg* pQueryMsg, SSqlObj *pSql, char
       assert(index >= 0);
 
       SVgroupInfo* pVgroupInfo = NULL;
-      if (pTableMetaInfo->vgroupList->numOfVgroups > 0) {
+      if (pTableMetaInfo->vgroupList && pTableMetaInfo->vgroupList->numOfVgroups > 0) {
         assert(index < pTableMetaInfo->vgroupList->numOfVgroups);
         pVgroupInfo = &pTableMetaInfo->vgroupList->vgroups[index];
+      } else {
+        tscError("%p No vgroup info found", pSql);
+        
+        *succeed = 0;
+        return pMsg;
       }
 
       vgId = pVgroupInfo->vgId;
@@ -948,8 +953,13 @@ int tscBuildQueryMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
     pQueryMsg->secondStageOutput = 0;
   }
 
+  int32_t succeed = 1;
+  
   // serialize the table info (sid, uid, tags)
-  pMsg = doSerializeTableInfo(pQueryMsg, pSql, pMsg);
+  pMsg = doSerializeTableInfo(pQueryMsg, pSql, pMsg, &succeed);
+  if (succeed == 0) {
+    return TSDB_CODE_TSC_APP_ERROR;
+  }
   
   SSqlGroupbyExpr *pGroupbyExpr = &pQueryInfo->groupbyExpr;
   if (pGroupbyExpr->numOfGroupCols > 0) {
@@ -2064,19 +2074,23 @@ int tscProcessSTableVgroupRsp(SSqlObj *pSql) {
     assert(pInfo->vgroupList != NULL);
 
     pInfo->vgroupList->numOfVgroups = pVgroupMsg->numOfVgroups;
-    for (int32_t j = 0; j < pInfo->vgroupList->numOfVgroups; ++j) {
-      //just init, no need to lock
-      SVgroupInfo *pVgroups = &pInfo->vgroupList->vgroups[j];
+    if (pInfo->vgroupList->numOfVgroups <= 0) {
+      tfree(pInfo->vgroupList);
+    } else {
+      for (int32_t j = 0; j < pInfo->vgroupList->numOfVgroups; ++j) {
+        //just init, no need to lock
+        SVgroupInfo *pVgroups = &pInfo->vgroupList->vgroups[j];
 
-      SVgroupMsg *vmsg = &pVgroupMsg->vgroups[j];
-      pVgroups->vgId = htonl(vmsg->vgId);
-      pVgroups->numOfEps = vmsg->numOfEps;
+        SVgroupMsg *vmsg = &pVgroupMsg->vgroups[j];
+        pVgroups->vgId = htonl(vmsg->vgId);
+        pVgroups->numOfEps = vmsg->numOfEps;
 
-      assert(pVgroups->numOfEps >= 1 && pVgroups->vgId >= 1);
+        assert(pVgroups->numOfEps >= 1 && pVgroups->vgId >= 1);
 
-      for (int32_t k = 0; k < pVgroups->numOfEps; ++k) {
-        pVgroups->epAddr[k].port = htons(vmsg->epAddr[k].port);
-        pVgroups->epAddr[k].fqdn = strndup(vmsg->epAddr[k].fqdn, tListLen(vmsg->epAddr[k].fqdn));
+        for (int32_t k = 0; k < pVgroups->numOfEps; ++k) {
+          pVgroups->epAddr[k].port = htons(vmsg->epAddr[k].port);
+          pVgroups->epAddr[k].fqdn = strndup(vmsg->epAddr[k].fqdn, tListLen(vmsg->epAddr[k].fqdn));
+        }
       }
     }