This issue is commonly encountered in Doris 2.1.x versions, particularly when using older versions of the MySQL Connector/NET driver.

The root cause is that Connector/NET 8.0.26 does not support the utf8mb3 character set, which Doris uses by default in some internal configurations. This results in the error:

Character set 'utf8mb3' is not supported by .NET Framework

✅ Solution Upgrade your MySQL Connector/NET driver to version 8.0.32 or later. This version includes support for the utf8mb3 character set and resolves the compatibility issue.

After upgrading the driver, restart Power BI and try connecting again. The issue should be resolved.