Message type: E = Error
Message class:  CNV_12000 - Messages for shorttext and description conversion 
Message number: 002
Message text: Old value for text &1 language &2 field &3 was &4
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_12000002 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 is a mismatch or inconsistency in the data being processed, specifically related to text fields in different languages.
Cause: The error message CNV_12000002 Old value for text &1 language &2 field &3 was &4 suggests that: The system is trying to update or convert a text field for a specific language, but the old value in the database does not match the expected value. This could be due to: Data inconsistencies in the source system. Incorrect mapping of fields during the migration process. Missing translations for the specified language. Data being modified in the target system while the migration is in progress.
Solution: To resolve this error, you can take the following steps: Check Data Consistency: Verify the data in the source system to ensure that the values for the specified
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNV_12000001 Changed Descriptions for &1
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_12000000 ERROR &1
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_12000003 New value for text &1 language &2 field &3 is &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_12000004 Old value for text &1 field &2 was &3
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.