n4pst3r3r

Hi everyone, I printed some card holders lately, like the one that can bee seen in the attached picture on the left hand side. On the right hand side is the same card holder, but printed in a 4x4 array with the same settings otherwise. Does anyone have an idea how this could have happened? Slicer was Cura (that's why I'm asking in this forum), printer an Anet A8 with Marlin. The settings were pretty much the default ones, 8mm rim, 0.1mm layer height. At first I thought it could have been the adaptive layer height, has I had it switched on the first time it came out so badly, but the result was the same after switching it off. Any ideas are appreciated ?