Message type: E = Error
Message class:  /SMB/MD_AS_CUST -  
Message number: 028
Message text: Start of log: After Import meth for Transport of Non Customizing Objects
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 /SMB/MD_AS_CUST028 typically occurs during the import of non-customizing objects, particularly when there are issues related to the transport of metadata or configuration settings. This error can arise in various scenarios, such as when there are inconsistencies in the transport request, missing dependencies, or issues with the target system's configuration.
Cause: Missing Dependencies: The transport request may depend on other objects or configurations that are not present in the target system. Inconsistent Data: There may be inconsistencies in the data being transported, such as mismatched versions or configurations. Authorization Issues: The user performing the import may not have the necessary authorizations to complete the operation. Transport Directory Issues: Problems with the transport directory or transport management system can also lead to this error. System Configuration: The target system may not be properly configured to accept the transported objects.
Solution: Check Dependencies: Ensure that all dependent objects are included in the transport request. You may need
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
/SMB/MD_AS_CUST027 After Import Method: End of process in client &1
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SMB/MD_AS_CUST026 RFC Connection for client &1 not defined
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SMB/MD_AS_CUST029 End of log: After Import method for Transport of Non Customizing Objects
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SMB/MD_AS_CUST030 Error when calling RFC &1: &2&3&4
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.