Message type: E = Error
Message class:  SD_FREE_GOODS_MSG - Message class for Free Goods maintenance 
Message number: 028
Message text: Additional material for free goods is required.
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.
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The SAP error message SD_FREE_GOODS_MSG028 indicates that additional material for free goods is required in the sales order or delivery process. This typically occurs in the context of free goods promotions where a certain quantity of paid goods entitles the customer to receive additional goods for free.
Cause: The error usually arises due to one of the following reasons: Incomplete Configuration: The free goods determination procedure may not be correctly configured in the system. Missing Free Goods Item: The sales order does not have the necessary free goods item added, or the conditions for free goods are not met. Incorrect Quantity: The quantity of the paid goods does not meet the threshold required to trigger the free goods. Master Data Issues: The material master data for the free goods may not be set up correctly, or the free goods item may not be linked properly to the main item.
Solution: To resolve the error, you can take the
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