The bug

The category containing the director Jakob Porsér under Mojang Alumni is titled Project Directors, and is incorrectly pluralized, as there is only one person who is in the category.

Here is a part of the credits that demonstrates the bug:

Project Directors
   Jakob Porsér

Fix

The title should be Project Director to be consistent with other titles that contain only one director.

Project Director
   Jakob Porsér

I am going to attach a resource pack with the fix for this issue.