Message type: E = Error
Message class:  MDG_BS_MAT_SI - Message Class : Material Replication Services Implementation 
Message number: 018
Message text: Quantity characteristic unit code for dimensions must be the same
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The SAP error message MDG_BS_MAT_SI018 indicates that there is a mismatch in the unit of measure (UoM) for quantity characteristics when working with material data in the Master Data Governance (MDG) module. This error typically arises when the system expects certain dimensions (like length, weight, volume, etc.) to be expressed in the same unit of measure, but they are not.
Cause: Inconsistent Units of Measure: The error usually occurs when the quantity characteristics for a material are defined with different units of measure. For example, if you have a dimension defined in kilograms and another in grams, the system will raise this error.
Configuration Issues: There may be issues in the configuration of the material master data or the way the characteristics are set up in the MDG system. Data Entry Errors: Incorrect data entry during the creation or modification of material data can lead to this error.
Solution: Check Quantity Characteristics: Review the quantity characteristics
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