LED technology offers building owners and facility managers opportunities to providing lighting effects impossible with traditional sources. Combined with control systems, the possibilities are almost endless. However, so too are the potential problems. This presentation will examine where things go wrong when characteristics of LED lighting are not fully considered. For example, legacy wiring and equipment can often create unexpected performance problems while forgotten bits of old control software can also create havoc. New features often provide unexpected consequences. Numerous field examples will be discussed, showing what can go wrong and how to avoid many of the problems.