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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 match. This can be done using the following steps: 

  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"

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: December 2018