'PowerBI - cannot 'Mark as date table'

I created a mysql date table. The primary key is a column of (mysql) type date. Now I added this date table to powerbi and wanted to mark it as date table. The validation passed, but the OK button is inactive, as one can see in the image:

enter image description here

What I am missing please?



Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source