Message type: E = Error
Message class:  /BOBF/CONF -  
Message number: 159
Message text: Class &1 inherits from obsolete library class &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 /BOBF/CONF159 Class &1 inherits from obsolete library class &2 indicates that a class in the Business Object Processing Framework (BOPF) is inheriting from a library class that has been marked as obsolete. This typically occurs when the underlying framework or libraries have been updated, and certain classes have been deprecated or replaced with newer versions.
Cause: Obsolete Library Class: The class that your custom or standard class is inheriting from has been marked as obsolete in the SAP system. This can happen during system upgrades or when SAP deprecates certain functionalities. Custom Development: If you have custom classes that extend or use obsolete classes, this error may arise when the system checks for compatibility.
Solution: Identify the Classes: Check the class definitions for both the class that is causing the error (&1) and the obsolete class (&2). You can do this using transaction SE24 (Class Builder). Update Inheritance: Modify the class definition
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
/BOBF/CONF158 Library class &1 is obsolete
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/BOBF/CONF157 Field &1 of alternative key &2 node &3 is not mapped to any proxy field
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/BOBF/CONF160 &1 must include &2
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/BOBF/CONF161 &1 must be of line type &2
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.