Upgrade from 1.5.3 to 1.5.4

There's a change in database structure change in version 1.5.4 for the Releasing Grade Function.

To upgrade from 1.5.3 to 1.5.4, please download 1.5.4 and then overwrite all existing files. Then run this SQL syntax in the database:

ALTER TABLE `simple_evaluation_marks` ADD `grade_release`
INT( 1 ) ;

Then everything should work...