Message type: E = Error
Message class:  NAA - Subsequent settlement (Purchasing) 
Message number: 326
Message text: No business volume tolerance group is assigned to user group &1
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 NAA326 indicates that there is no business volume tolerance group assigned to the specified user group. This error typically arises in the context of SAP's business volume management, which is used to control and monitor business transactions based on predefined tolerances.
Cause: The error occurs when: A user group is trying to perform an action that requires a business volume tolerance group, but none has been assigned to that user group. The configuration settings in the SAP system for business volume management are incomplete or incorrect.
Solution: To resolve the NAA326 error, you can follow these steps: Check User Group Configuration: Go to the SAP transaction code SU01 (User Maintenance) or PFCG (Role Maintenance). Verify the user group associated with the user who is encountering the error. Ensure that the user group is correctly defined and active. Assign a Business Volume Tolerance Group: Navigate to the configuration settings for business volume management. This can typically be found in
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
NAA325 Enter an arrangement type (see F4 help)
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
NAA324 Enter a business volume tolerance group (see F4 help)
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
NAA327 All condition records are dependent on business volume (no settlement)
What causes this issue?  All condition records of arrangement &V1& belong to condition types that are independent of business volume. Settleme...
NAA328 Condition type &3 is dependent on bus. volume (no cond.rec. settlement)
What causes this issue?  Arrangement &V1& has condition records for condition types of which condition type &V3& is business-volume-in...
Click on this link to search all SAP messages.