If the call succeeds, ApsaraMQ for MQTT the system returns ResponseCode=200 to the client. If the call fails, the corresponding error code and description are returned. You can find solutions based on the error codes listed in the following table.

Token error codes

HTTP status codeErrorError messageDescription
404ApiNotSupportThe specified API is not supported.The current interface is not supported. Please check.
400ApplyTokenOverFlowYou have applied for tokens too many times. Please try again later.token application frequency is too high, system flow control, please try again.
400CheckAccountInfoFailedAn error occurred while checking the account information by the STS token.An error occurred while parsing the account information in the STS token.
400InstancePermissionCheckFailedAn error occurred while validating the permissions of the instance. Please verify the account that created the instance and its permissions settings.Failed to verify the instance permissions. ApsaraMQ for MQTT The ownership of the instance and the authorization policy.
500InternalErrorAn error occurred while processing your request. Try again later.ApsaraMQ for MQTT The backend service is abnormal. Try again later.
400ParameterCheckFailedAn error occurred while validating the parameters. The parameters may be missing or invalid.The parameter verification fails. This parameter may be missing or invalid.
400PermissionCheckFailedAn error occurred while validating the resource permissions. Please check the account that created the instance, topic, and GroupId, and check their permission settings.The error message returned because the resource permission verification failed. Check the instance, Topic, and Group ID for their permissions and authorization policies.
500SystemOverFlowAn error occurred while processing your request. Please try again.System throttling. Please try again.
400InvalidParameter.%sAn error occurred while validating the parameter. The parameter may be missing or invalid.The parameter verification fails. This parameter may be missing or invalid.

Group ID error codes

HTTP status codeErrorError messageDescription
500CreateGroupIdErrorFailed to create GroupId. Try again later.The request to create a Group ID failed. Try again later.
400GroupIdAlreadyExsitedThe specified GroupId already exists. The current Group ID already exists.
400GroupIdAlreadyUsedByOtherUsersThe current GroupId is used by another user. Please change to a different GroupId.The specified Group ID is already owned by another user.
500InternalErrorAn error occurred while processing your request. Try again later.The MQTT backend service is abnormal. Please try again.
400ParameterFieldCheckFailedFailed to validate the parameters. The parameters may be missing or invalid.The parameter verification fails. This parameter may be missing or invalid.
400InstancePermissionCheckFailedAn error occurred while validating the permissions of the instance. Please verify the account that created the instance and its permissions settings.Failed to verify the instance permissions. ApsaraMQ for MQTT The ownership of the instance and the authorization policy.
400InstanceNotFoundFailed to find the instance. The instanceId may be invalid.Unable to find instance.
400PermissionCheckFailedAn error occurred while validating the resource permissions. Please check the account that created the instance, topic, and GroupId, and check their permission settings. The error message returned because the resource permission verification failed. Check the instance, Topic, and Group ID for their permissions and authorization policies.

For a list of error codes, visit the API Error Center.