Message type: E = Error
Message class:  FMBAS - FM applic. specific messages for Budgeting & AVC services 
Message number: 052
Message text: Cover groups are only allowed for control objects or RIB rules
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 FMBAS052 indicates that cover groups are being used incorrectly in the context of the Financial Management (FM) module. Specifically, this error occurs when cover groups are applied to objects that are not control objects or RIB (Revenue Integration and Budgeting) rules.
Cause: The error arises when: You attempt to assign a cover group to a budget or commitment item that is not classified as a control object. The system expects cover groups to be used only with specific types of objects, such as control objects or RIB rules, and the object you are working with does not meet these criteria.
Solution: To resolve this error, you can take the following steps: Check Object Type: Verify that the object you are trying to assign the cover group to is indeed a control object or a valid RIB rule. If it is not, you will need to either: Change the object to a valid type that
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
FMBAS051 Entry not allowed: element &1 is not active
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FMBAS050 Call of method &1 not allowed in class &2
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FMBAS053 Automatic cover group &1 does not exist
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FMBAS054 Automatic cover group &1 cannot be used for control ledger &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.