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DRAFT KB - XXXX Illegal mix of collations (utf8mb4_unicode_ci,COERCIBLE) and (utf8mb4_general_ci,COERCIBLE) causes failure to load a view


The following error displays in the browser while trying to load a record or report: 

#1267 - Illegal mix of collations (utf8mb4_unicode_ci,COERCIBLE) and (utf8mb4_general_ci,COERCIBLE) for operation 'substring_index'


This issue is seen when the tables called by the view have a different collation setup. 


Ensure that the collation of all the tables matches. If this issue occurs in a cloud site follow the steps here:  

  1. Access the database (https://<SITE-NAME>/database)
  2. Navigate to the table which is throwing the error.
  3. Open the "Operation" tab for the table.
  4. Set the Collation under "Table Option"

If this occurs in an on-premise environment, engage the DBA team responsible for maintaining the database.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: December 2018