Message type: E = Error
Message class:  /SCMB/MC_PB_DEF -  
Message number: 023
Message text: Entry &1: Enter a unit of measure for maximum package height
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 /SCMB/MC_PB_DEF023 Entry &1: Enter a unit of measure for maximum package height typically occurs in the context of SAP Supply Chain Management (SCM) when dealing with packaging or logistics data. This error indicates that a required field for the maximum package height has not been filled out correctly, specifically the unit of measure (UoM) for that height.
Cause: Missing Unit of Measure: The most common cause of this error is that the unit of measure for the maximum package height has not been specified in the relevant configuration or master data. Incorrect Configuration: There may be an issue with the configuration of the packaging material or the product master data where the unit of measure is not defined. Data Entry Error: During data entry, the user may have overlooked entering the unit of measure for the maximum package height.
Solution: Check Packaging Data: Navigate to the relevant packaging data in the SAP
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
/SCMB/MC_PB_DEF022 Access to product master data failed
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SCMB/MC_PB_DEF021 Data was saved
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SCMB/MC_PB_DEF024 Entry &1: Enter a unit of measure for maximum package weight
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SCMB/MC_PB_DEF025 Entry &1: Product &2 doesn't exist
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.