I get this all the time too. I have redownloaded royals 4 times and it works for about a day until it happens again...
I may as well make a thread about this specific error. I can tell you guys that this issue is easily fixed by toggling Compatibility Mode in the Properties of Mapleroyals. All you have to do is toggle it by checking/un-checking the box and then hitting apply. Mapleroyals should be able to open after the first attempt. If it doesn't, try the same thing again.