Fatal error when using the game module

When trying to use any of the games created (doesn't matter if hangman, crossword etc) the module fails with the following message:

Notice: Undefined variable: DB in x:\inet\uat\Wi_Moodle_2\mod\game\header.php on line 15 Fatal error: Call to a member function get_record() on a non-object in x:\inet\uat\Wi_Moodle_2\mod\game\header.php on line 15

I'm running game mod 2013071501 (3.7.15). Server is W2k8R2 (IIS) with MS SQL 2008.