Despite those desirable features, the new Aviatik fighter wasn't greeted with enthusiasm when it entered service in autumn 1917, as the type also had some serious defects which didn't endear it to its pilots. The early aircraft had structural deficiencies and their machine guns were installed beyond the reach of the pilot so that when they jammed, there was nothing the pilot could do about it. These problems were later rectified with the strengthening of the airframe and the repositioning of the guns. While the original Aviatik D-I design by Julius von Berg was sound, the Series 115 aircraft license-produced by the Lohner firm at Wien-Floridsdorf were notorious for failures along the wing trailing edges in high speed maneuvers, as Lohner had deviated from Aviatik specifications by employing thinner, lighter wing ribs. The main cause of complaints was the engine's tendency to overheat far too easily. To alleviate these cooling problems, operational units tended to fly their aircraft without the engine's top panels and sometimes the side panels were also left off.