How To Fix MC821 - Technical layout & & and technical layout of proxy view & do not match

SAP Error Message - Details

• Message type: E = Error

• Message class: MC - Aggregate: views, matchcodes, lock objects

• Message number: 821

• Message text: Technical layout & & and technical layout of proxy view & do not match

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message MC821 - Technical layout & & and technical layout of proxy view & do not match ?

  The SAP error message MC821 typically indicates a mismatch between the technical layout of a data source and the technical layout of the corresponding proxy view in the context of SAP BW (Business Warehouse) or SAP BI (Business Intelligence). This error can occur during data extraction or when trying to load data into a data target.
  Cause:
  
  Mismatch in Data Structure: The technical layout of the data source (e.g., InfoSource, DataSource) does not match the technical layout of the target (e.g., InfoProvider, DSO, or InfoCube). This can happen if there have been changes made to the data source or the target structure without corresponding updates to the other.
  Changes in Fields: If fields have been added, removed, or modified in either the data source or the target, it can lead to this error.
  Versioning Issues: If there are different versions of the data source or target being used, it can lead to inconsistencies.
  Transport Issues: If changes were transported from one system to another (e.g., from development to production) without ensuring that both systems are in sync, this error can occur.
  
  Solution:
  
  Check Technical Layouts: Compare the technical layout of the data source and the target. Ensure that they match in terms of field names, data types, and lengths.
  Update Data Source: If changes have been made to the data source, ensure that the corresponding changes are reflected in the target. This may involve updating the InfoProvider or DSO.
  Re-activate DataSource: Sometimes, simply reactivating the DataSource in the SAP BW system can resolve the issue. This can be done in the Data Warehousing Workbench.
  Check for Transport Issues: Ensure that all relevant transports have been correctly applied and that both the source and target systems are in sync.
  Use Transaction RSA1: Go to the Data Warehousing Workbench (transaction RSA1) and check the DataSource and InfoProvider settings. You can also use the "Activate" option to refresh the technical settings.
  Check for Field Mapping: If you are using transformations, ensure that the field mapping is correct and that all required fields are included.
  
  Related Information:
  
  Transaction Codes: 
  
  RSA1: Data Warehousing Workbench
  RSO2: Maintain DataSource
  RSD1: InfoProvider Maintenance
  
  
  SAP Notes: Check for any relevant SAP Notes that might address specific issues related to this error.
  Documentation: Review SAP documentation for data modeling and data extraction processes to ensure best practices are being followed.
  
  If the issue persists after trying the above solutions, it may be beneficial to consult with your SAP Basis or BW team for further investigation, as they may have access to logs and additional tools to diagnose the problem.