After upgrading from m2.1.1 to m2.1.3 the category pages, which are accessible [shop-url]/[categoryname].html are empty. ### Preconditions <!--- Provide a more detailed information of environment you use --> <!--- Magento version, tag, HEAD, etc., PHP & MySQL version, etc.. --> 1. m2.1.1 had theme SM_market v2.3.0 installed; m2.1.3 SM_market v2.5.2 2. Products and Cetegories were defined and produced expected results (listing) ### Steps to reproduce 1. Go to https://devl.kouki.ch 2. Under "Kategorien" select "Wäschetransport" --> nothing. Category contains 165 products. 3. ### Expected result <!--- Tell us what should happen --> 1. Listing of the products in the Category ### Actual result <!--- Tell us what happens instead --> 1. Empty page with title <!--- (This may be platform independent comment) -->