So I downloaded this game for the first time, but when I double clicked the MapleRoyals file and gave it access to my computer or whatever, nothing happened. I tried the same thing with the MapleStory file, and nothing happened.
Make sure your anti-virus software isn't blocking,quarantining, or deleting the files. One of the files usually gets caught. Just have to allow that and it'll work fine.
Make sure you go through Avast and see if it already deleted the files, though. And restore them if possible. Or look and see if you have any other virus software installed and try to go through those. When I was originally having the no-launch issue, it was always related to my anti-virus software removing a certain file. I'm assuming it's the same for most people.