Message type: E = Error
Message class:  /SAPAPO/MSDP_SEASON -  
Message number: 012
Message text: Season year &1 locked by user &2
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 /SAPAPO/MSDP_SEASON012 indicates that a specific season year is locked by a user, which prevents other users from making changes or accessing that season year. This is a common issue in SAP Advanced Planning and Optimization (APO) when multiple users are working on planning data simultaneously.
Cause: The error occurs when: A user has locked a specific season year for editing, and another user attempts to access or modify that same season year. The lock is typically placed when a user is performing actions such as planning, data entry, or running reports that involve that season year.
Solution: To resolve this issue, you can take the following steps: Identify the Locking User: Check who is currently locking the season year. The error message provides the user ID (&2) that has locked the season year (&1). Contact the Locking User: If possible, reach out to the user who has locked the season year and ask them
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
/SAPAPO/MSDP_SEASON011 No authorization for changing season years
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPAPO/MSDP_SEASON010 Error when deleting season &1
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPAPO/MSDP_SEASON013 Error when saving season year &1
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPAPO/MSDP_SEASON014 Season year &1 has been saved successfully
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.