If you have a Virus Scanner that Says you had received the Virus Win32/Themida from patching Maple. Its Not a Virus. Don't Worry. Its Just something that automatically detected a so called "Crack" for a Game. Thats what the file had been masked as when installed. If you Remove from your system the threats you have to re-download The Client is Deleted also and you have to re-download.
If you receive you Do not Have permissions or Anything of the above the Advised things you must do to fix the issue is:
BEST THING AND WORKED FOR ME AFTER HOURS Here is the best Guide you will find.http://www.basilmarket.com/forum/1278242/1/PuppyKevins_Guide_to_Fix_Your_Antivirus_Problems.html#After that you should be Good to play.
Random DC's In Game-
It will usually Stop after a while, My Guess is Too many log in's at once since it is evening time and everyone is trying to log on. It is Confirmed that the DC stops after a bit.