Issue

After deploying a package to Mendix Cloud, the application does not start. The Error (SQL State: 23505, Error Code: 0)error is shown in the logs as follows:

2024-11-22T14:06:55.318560 [APP/PROC/WEB/0] ERROR: Executing execute_ddl_commands did not succeed: result: 1, 
2024-11-22T14:06:55.318816 [APP/PROC/WEB/0] ERROR: Starting application failed: Application start failed
2024-11-22T14:06:55.319224 [APP/PROC/WEB/0] ERROR - M2EE: An error occurred while executing action 'Execute DDL commands'.
2024-11-22T14:06:55.319251 [APP/PROC/WEB/0] com.mendix.m2ee.api.AdminException: Executing DDL commands failed.
2024-11-22T14:06:55.319402 [APP/PROC/WEB/0] Caused by: com.mendix.basis.connectionbus.ConnectionBusException: Error (SQL State: 23505, Error Code: 0) on executing:
2024-11-22T14:06:55.319413 [APP/PROC/WEB/0] INFO: Waiting for the application to shutdown…
2024-11-22T14:06:55.319747 [APP/PROC/WEB/0] All changes are rolled back.

Environment

Applications hosted in Mendix Cloud

Cause

A unique constraint ensures that values in a column do not duplicate across rows in a database table. If this unique constraint is violated, the error described above occurs since the application attempted to insert or update a duplicate record in a column with a unique constraint.

Solution/Workaround

To solve the error, follow these steps:

1. Identify and remove any duplicate record in the table. Please note that Mendix Support cannot assist in this step.
2. Build the package again.
3. Deploy the package to the environment. 

Additional information

• Mendix documentation: Deploying an App to Mendix Cloud
• Related KBA: Deployment issue due to timeout in application startup on the Mendix Public Cloud