Hello! I had this problem. What i had to do is go to the maplestory installation folder, and change the name of the folder it was installed.
E.g., on my PC, maplestory was installed on D:\Games\Nexon\Library\maplestory\appdata.
What i did was change the "appdata" folder name to "app". Restart aries.exe client and it should work. Hope it helps.
