Message type: E = Error
Message class:  CNV_NCE_BAS - Number conversion engine: messages 
Message number: 122
Message text: New mapping values for subobject &1
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 CNV_NCE_BAS122 typically occurs during data migration or conversion processes, particularly when using the SAP S/4HANA Migration Cockpit or other data migration tools. This error indicates that there are new mapping values for a subobject that have not been defined or are missing in the mapping configuration.
Cause: Missing Mapping Values: The error usually arises when the system encounters a subobject that requires a mapping value that has not been defined in the migration settings. Inconsistent Data: The source data may contain values that do not have corresponding mappings in the target system.
Configuration Issues: There may be issues in the configuration of the migration project, such as missing or incorrect mapping rules.
Solution: Check Mapping Configuration: Go to the migration project in the SAP S/4HANA Migration Cockpit. Review the mapping settings for the specific subobject indicated in the error message. Ensure that all necessary mapping values are defined and correctly configured. Define Missing Values: If the error
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNV_NCE_BAS121 &1 &2 &3 &4
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_NCE_BAS120 Initialization of number range mapping values started in background
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_NCE_BAS123 Changes detected in table NRIV, initialization of mappings is required
What causes this issue?  The system has detected that table NRIV have been changed since the activity <ZK>Initialize Mapping Values for Number R...
CNV_NCE_BAS124 Cannot retrieve subobject mapping values
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
Click on this link to search all SAP messages.