Message type: E = Error
Message class:  /MVA/AMVIAMSG -  
Message number: 012
Message text: The correction has not be assigned to an inquiry yet
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 /MVA/AMVIAMSG012 indicates that a correction has not been assigned to an inquiry in the context of the SAP Advanced Planning and Optimization (APO) module, specifically related to the Demand Planning (DP) or similar functionalities. This error typically arises when there is an attempt to process a correction or adjustment that has not been linked to a specific inquiry or planning object.
Cause: Unassigned Correction: The correction you are trying to apply is not linked to any existing inquiry or planning object. Data Integrity Issues: There may be issues with the data integrity or configuration that prevent the system from recognizing the relationship between the correction and the inquiry. User Error: The user may have attempted to apply a correction without first creating or selecting the appropriate inquiry.
Solution: Check Inquiry Assignment: Ensure that the correction you are trying to apply is properly assigned to an inquiry. You may need to create a
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
/MVA/AMVIAMSG011 The answer has not been assigned to an inquiry
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/MVA/AMVIAMSG010 Copy Inquiry action, the notification cannot have status "Open"
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/MVA/AMVIAMSG026 Cancellation during import; input medium &1 empty (may be wrong format)
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/MVA/AMVIAMSG035 No values for this selection
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.