Message type: E = Error
Message class:  /SAPAPO/OM_PVC_BASE -  
Message number: 016
Message text: PVC handle already been registered for at the current session
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/OM_PVC_BASE016 indicates that a PVC (Process Variant Configuration) handle has already been registered for the current session. This typically occurs in the context of SAP Advanced Planning and Optimization (APO) when there is an attempt to register a PVC handle that is already in use.
Cause: Multiple Registrations: The error usually arises when a user or process tries to register the same PVC handle multiple times within the same session. Session Management Issues: It can also occur due to session management issues, where the session does not properly release or deregister the PVC handle after its use. Concurrency Issues: If multiple processes or users are trying to access the same PVC handle simultaneously, it may lead to this error.
Solution: Check for Existing PVC Handle: Before attempting to register a PVC handle, check if it is already registered in the current session. You can do this by reviewing the session state or
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
/SAPAPO/OM_PVC_BASE015 Negative value for max_num of selection results
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPAPO/OM_PVC_BASE014 Source and target planversion are the same
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPAPO/OM_PVC_BASE017 PVC handle is marked for delete
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPAPO/OM_PVC_BASE018 Session is being terminated, only deleteHandle allowed
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.