Unable to delete the database of a domain in Plesk: Directory not empty

Symptoms

An attempt to delete the database of a Plesk domain via the Plesk GUI results in an error that is similar to the following:

PLESK_ERROR: Error: Unable to remove some of the selected databases. SQLSTATE[HY000]: General error: 1010 Error dropping database (can't rmdir '.\jdoe_test', errno: 41 "Directory not empty")

Cause

Extra files exist in the database folder and this prevents the expected removal of the entire directory from occurring.

Resolution

1. Connect to the server via SSH
2. Remove any extra files from the directory of the affected database
3. Repeat the database deletion action via the Plesk GUI