If the call succeeds, Message Queue for MQTTthe 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 following error codes.

Token error codes

HTTP status code Error code Error message Description
404 ApiNotSupport The specified API is not supported. The current interface is not supported. Please check.
400 ApplyTokenOverFlow You have applied for tokens too many times. Please try again later. token application frequency is too high, system flow control, please try again.
400 CheckAccountInfoFailed An error occurred while checking the account information by the STS token. An error occurred while parsing the account information in the STS token.
400 InstancePermissionCheckFailed An 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. Message Queue for MQTTThe ownership of the instance and the authorization policy.
500 InternalError An error occurred while processing your request. Try again later. Message Queue for MQTTThe backend service is abnormal. Try again later.
400 ParameterCheckFailed An error occurred while validating the parameters. The parameters may be missing or invalid. The parameter verification fails. This parameter may be missing or invalid.
400 PermissionCheckFailed An 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.
500 SystemOverFlow An error occurred while processing your request. Please try again. System throttling. Please try again.
400 InvalidParameter.%s An 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 code Error code Error message Description
500 CreateGroupIdError Failed to create GroupId. Try again later. The request to create a Group ID failed. Try again later.
400 GroupIdAlreadyExsited The specified GroupId already exists. The current Group ID already exists.
400 GroupIdAlreadyUsedByOtherUsers The current GroupId is used by another user. Please change to a different GroupId. The specified Group ID is already owned by another user.
500 InternalError An error occurred while processing your request. Try again later. The MQTT backend service is abnormal. Please try again.
400 ParameterFieldCheckFailed Failed to validate the parameters. The parameters may be missing or invalid. The parameter verification fails. This parameter may be missing or invalid.
400 InstancePermissionCheckFailed An 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. Message Queue for MQTTThe ownership of the instance and the authorization policy.
400 InstanceNotFound Failed to find the instance. The instanceId may be invalid. Unable to find instance.
400 PermissionCheckFailed An 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.