Unable to create customer or access Application Vault in Plesk: Access denied for user ‘apsc’@’localhost’

Symptoms

• It is not possible to create a new customer. The operation fails with the following error:

  external error: ODBC error #HY000: [MySQL][ODBC 3.51 Driver]
  Access denied for user 'apsc'@'localhost' (using password: YES)

• A similar error appears when creating a subscription, installing an APS application or accessing Application Vault at Tools & Settings:

  external error: ODBC error #HY000: [MySQL][ODBC 3.51 Driver]
  Access denied for user 'ODBC'@'localhost' (using password: NO)
  ODBC error #HY000: [MySQL][ODBC 3.51 Driver]
  Access denied for user 'ODBC'@'localhost' (using password: NO)
  ODBC error #HY000: File aps_php.php Line 11933
  Type Exception

• The following warning may appear in Tools & Settings > Backup Manager > View the log:

  Warning: Domain "example.com"
  Unable to back up applications. Error: ODBC error #28000: [unixODBC][ma-3.0.8]Access denied for user 'apsc_jdoe'@'localhost' (using password: YES)

Cause

Password for the apsc database user is set to the incorrect value, or is missing.

Resolution

1. Connect to the server using SSH or RDP

2. Use the self-repair tool:

   # plesk repair db

   OR

   C:> plesk repair db