I use OpenStreetMap Carto in Tilemill in order to export mbtiles for a small town. I managed to setup everything according to the installation guide. However, when I open the OpenStreetMap Carto project in Tilemill I only get a blue background which is set by Map {background-color: @water-color;} in style.mss. Other than that there is no rendered map to be seen. I checked my database in QGIS and there it looks ok. Since I'm very new to this, I've no idea where to look for the problem. Any suggestions?
PS: I had a problem similar to this one: Error with TileMill and OpenStreetMap Carto project, and was able to resolve it by the suggested solutions the result being that the errors didn't show up but I ended up with the map showing only its blue background.