diff --git a/utils/filemgmt_libn/include/n_error.h b/utils/filemgmt_libn/include/n_error.h
index e4f624e2bd04719b705718a762414544c1b93bf5..ea88f0354537c79a25479e0272bfa6a40370db9f 100644
--- a/utils/filemgmt_libn/include/n_error.h
+++ b/utils/filemgmt_libn/include/n_error.h
@@ -160,7 +160,9 @@ enum ErrCodeSuffixOfDistributedFile {
     E_NETWORK_ERR,
     E_BATTERY_WARNING,
     E_EXCEED_MAX_LIMIT,
-    E_DATABASE_FAILED
+    E_INNER_ERROR,
+    E_OTHER_TASK_RUNNING,
+    E_VERSION_FILE_NO_EXIST,
 };
 
 enum CommonErrCode {
@@ -273,7 +275,8 @@ static inline std::unordered_map<int, std::pair<int32_t, std::string>> errCodeTa
     { EBADFD, { FILEIO_SYS_CAP_TAG + E_BADFD, "File descriptor in bad state" } },
     { ERESTART, { FILEIO_SYS_CAP_TAG + E_RESTART, "Interrupted system call should be restarted" } },
     { EDQUOT, { FILEIO_SYS_CAP_TAG + E_DQUOT, "Quota exceeded" } },
-    { UNKROWN_ERR, { FILEIO_SYS_CAP_TAG + E_UKERR, "Unknown error" } },
+    { UNKROWN_ERR, { FILEIO_SYS_CAP_TAG + E_UKERR, "Unknown error. Possible causes: 1.Insufficent memory"
+        "2.Memory operation error 3.Null pointer 4.Expected resources cannot be obtained" } },
     { ENOLCK, { FILEIO_SYS_CAP_TAG + E_NOLCK, "No record locks available" } },
     { ENETUNREACH, { FILEIO_SYS_CAP_TAG + E_NETUNREACH, "Network is unreachable" } },
     { ECONNECTIONFAIL, { FILEIO_SYS_CAP_TAG + E_CONNECTION_FAIL, "Connection failed" } },
@@ -324,7 +327,8 @@ static inline std::unordered_map<int, std::pair<int32_t, std::string>> errCodeTa
     { FILEIO_SYS_CAP_TAG + E_RESTART, { FILEIO_SYS_CAP_TAG + E_RESTART,
         "Interrupted system call should be restarted" } },
     { FILEIO_SYS_CAP_TAG + E_DQUOT, { FILEIO_SYS_CAP_TAG + E_DQUOT, "Quota exceeded" } },
-    { FILEIO_SYS_CAP_TAG + E_UKERR, { FILEIO_SYS_CAP_TAG + E_UKERR, "Unknown error" } },
+    { FILEIO_SYS_CAP_TAG + E_UKERR, { FILEIO_SYS_CAP_TAG + E_UKERR, "Unknown error. Possible causes:"
+        "1.Insufficent memory 2.Memory operation error 3.Null pointer 4.Expected resources cannot be obtained" } },
     { FILEIO_SYS_CAP_TAG + E_NOLCK, { FILEIO_SYS_CAP_TAG + E_NOLCK, "No record locks available" } },
     { FILEIO_SYS_CAP_TAG + E_NETUNREACH, { FILEIO_SYS_CAP_TAG + E_NETUNREACH, "Network is unreachable" } },
     { FILEIO_SYS_CAP_TAG + E_CONNECTION_FAIL, { FILEIO_SYS_CAP_TAG + E_CONNECTION_FAIL, "Connection failed" } },
@@ -357,7 +361,8 @@ static inline std::unordered_map<int, std::pair<int32_t, std::string>> errCodeTa
         "Member not exist" } },
     { USER_FILE_MANAGER_SYS_CAP_TAG + E_INPUT, { USER_FILE_MANAGER_SYS_CAP_TAG + E_INPUT,
         "Wrong input parameter" } },
-    { STORAGE_SERVICE_SYS_CAP_TAG + E_IPCSS, { STORAGE_SERVICE_SYS_CAP_TAG + E_IPCSS, "IPC error" } },
+    { STORAGE_SERVICE_SYS_CAP_TAG + E_IPCSS, { STORAGE_SERVICE_SYS_CAP_TAG + E_IPCSS,
+        "IPC error. Possible causes: 1.IPC communication failed or timeout 2.Failed to load the service" } },
     { STORAGE_SERVICE_SYS_CAP_TAG + E_NOTSUPPORTEDFS, { STORAGE_SERVICE_SYS_CAP_TAG + E_NOTSUPPORTEDFS,
         "Not supported filesystem" } },
     { STORAGE_SERVICE_SYS_CAP_TAG + E_MOUNT, { STORAGE_SERVICE_SYS_CAP_TAG + E_MOUNT, "Failed to mount" } },
@@ -412,8 +417,13 @@ static inline std::unordered_map<int, std::pair<int32_t, std::string>> errCodeTa
         E_BATTERY_WARNING, "Battery level warning" } },
     { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG + E_EXCEED_MAX_LIMIT, { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG +
         E_EXCEED_MAX_LIMIT, "Exceed the maximum limit" } },
-    { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG + E_DATABASE_FAILED, { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG +
-        E_DATABASE_FAILED, "Database operation failed" } },
+    { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG + E_INNER_ERROR, { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG +
+        E_INNER_ERROR, "Inner error. Possible causes: 1.Failed to access the database or execute the SQL statement."
+        "2.System error, such as null pointer, insufficent memory, memory operation error or JS engine exception." } },
+    { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG + E_OTHER_TASK_RUNNING, { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG +
+        E_OTHER_TASK_RUNNING, "There are other same tasks running" } },
+    { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG + E_VERSION_FILE_NO_EXIST, { DISTRIBUTEDFILE_SERVICE_SYS_CAP_TAG +
+        E_VERSION_FILE_NO_EXIST, "The version file used to replace original file does not exist." } },
 };
 
 class NError {