No data get_products() with filters #1

Filters return no data with get_products. Just get a blank page with no errors. Tried the following:

get_products( array( 'filter[posts_per_page]' => '-1' ) );
get_products( array( 'filter[q]' => 'search-term' ) );
get_products( array( 'filter[s]' => 'search-term' ) );
get_products( array( 'filter[created_at_min]' => '2013-12-01' ) );

Also tried all functions in the example.php all with 200 response and no php errors but no data.
The api is working as get_index() and get_products() both return data.