Message type: E = Error
Message class:  CNVMBT - Messages for MBT/API/PCL 
Message number: 053
Message text: Job has been restarted. See new subactivity to determine the state
Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.
To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.
Unfortunately, there isn't any extra information in this error notice.
First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).
Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.
You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.
The SAP error message CNVMBT053 indicates that a job has been restarted, and you need to check the new subactivity to determine the current state of the job. This message is typically associated with the SAP Migration Cockpit or data migration processes, particularly when using the SAP S/4HANA Migration tools.
Cause: Job Restart: The job may have been restarted due to various reasons, such as: A manual restart initiated by a user. A system error or timeout that caused the job to fail and subsequently restart. Resource constraints (e.g., memory, CPU) that led to the job being unable to complete successfully. Dependencies on other jobs or processes that may have caused a delay or failure.
Configuration Issues: There may be issues with the configuration of the migration job or the underlying data. Data Issues: Problems with the data being migrated, such as inconsistencies or errors in the source data.
Solution: Check Job Logs: Go to the job monitoring tool (Transaction
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNVMBT052 Table &1 does not exist in the receiver system
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNVMBT051 At least one user need the admininstrator status in table cnvmbtusr.
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNVMBT054 No masstransfer ID specified for subproject &1
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNVMBT055 Changes after defining convobject &1 will not be considered
 When you execute the activity "Define Conversion Objects", all settings concerning the conversion objects are saved. From now on any change...
Click on this link to search all SAP messages.