Some strange proble occures. On the website http://www.thedoglounge.nl we have a menu on the left side. In the categories "Halsbanden" and "Looplijnen" we have sub categories. When you click on "Halsbanden" subcategories will open without a problem. But "Looplijnen" suddenly disappears.
Same the other way around (after first selecting home at the top of the page), clicking on "Looplijnen" sub categories will appear normal but "Halsbanden" disappears.
And if you have clicked on "Halsbanden" or "Looplijnen" and you click on one other category, for example "Nieuw", both "Halsbanden" and "Looplijnen" disappear all together.
We do have the latest woocommerce installed with the latest WP. The theme loaded is whitelight bought at Woothemes