Confluence Does Not Start with 'Detected tables with non-default character encoding/collation' Message
Platform Notice: Data Center - This article applies to Atlassian products on the Data Center platform.
Note that this knowledge base article was created for the Data Center version of the product. Data Center knowledge base articles for non-Data Center-specific features may also work for Server versions of the product, however they have not been tested. Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.
*Except Fisheye and Crucible
Symptoms
Confluence does not start up when using MySQL database. One of the following errors is displayed:
- Detected tables with non-default character encoding.
- Detected tables with non-default collation.
Cause
Confluence 5.2.4 added a check for tables with character encoding or collation setting that differs from the database default settings. Using non-default setting in a table can cause upgrade process to fail and leave the database in an inconsistent state.
Resolution
Please see the How to Fix the Collation and Character Set of a MySQL Database manually knowledge base article and ensure that the database runs with unified character encoding and collation settings at all levels: database, table, and column.
From Confluence 7.3 and later, running on MySQL 5.7.9 or later, support to utf8mb4 was added. Make sure to select the appropriate encoding/collation to your system.