After searching and trying for days, I'm starting to get agitated..
I have a custom theme for Wordpress, wich seems to function OK. But after installing Woocommerce several widget don't work, such as the shopping cart and lightbox.
I found out that it has something to do with my theme not being compatible with Woocommerce because when I change to a standard theme everything works as expected.
On Woocommerce docs I saw I might have to add some hooks to my functions.php but I can't figure out where to add these hooks...
Can anyone point me in the right direction?