I recently wanted to get back into MapleRoyals so I tried to use my old launcher to get into the game. It didn't work so I re-downloaded it. Though when I tried to launch it a black screen would come up for about 5 seconds and then crash. I then tried to update the engine and update the wrapper (following this: http://royals.ms/forum/threads/mapleroyals-mac-client.273/) but it didn't work, so if anybody can help me (again) it would be greatly appreciated.
Ok, I've fixed the issue. For anybody wondering about this issue what I did to fix this was to uninstall Razer Synapse, because apparently Razer Synapse blocks applications on Mac this also includes osu as well as Mapleroyals.