This is indicating that either there is a problem with your internet connection, security software on your PC is blocking NProtect from accessing its patch server, or the NProtect patch server is temporarily down. Either re-download the game, or, Go to Internet>Settings>Network>Check security program on top is working or not.Also check if you need to get authorized to use the internet. Its installation might have been interrupted. GameGuard was corrupted during installation. Just delete your gameguard folder and re-download.
If you already allowed the things and still do not work. If the problem still persists, delete the GameGuard directory and run the MapleStory patcher again. Please be sure to allow NProtect access through your firewall. The NProtect patch process failed due to corrupted files, or an overly restrictive firewall. Please close MU and NProtect and load the game a new. This is indicating that the NProtect patches failed to download, either due to an overly restrictive firewall or network issues leading to failed downloads We recommend checking your firewall settings as well as your current connection stability, and trying again at a later time. We recommend deleting the GameGuard folder and re-running the Updater program again in order to redownload the NProtect files. Due to a problem with the GameGuard INI, the program was unable to launch. If you are unable to restore it, we recommend contacting a qualified PC technician to examine your PC. Please visit for assistance in restoring this file for your particular OS version. If it is encountered, your PC may have a severe virus or be experiencing Operating System / Hard Disk corruption. This error should not occur under Windows XP. Please delete the GameGuard folder and repatch, or update. Your installation of NProtect is either incomplete or damaged. You may also wish to try temporarily disabling any virus scanning, firewall, or security software on your PC. Also, you may wish to end any unnecessary system services or processes if you feel comfortable doing so. Please verify that you have administrative access to the PC you are using, and that you have shut down all nonessential software. In general, it is indicating that some software on your PC is preventing NProtect from loading. Unfortunately a specific solution to this error is unavailable.
You may wish to make sure your virus scanning program is up-to-date and functioning properly, and that you do not have too many other open programs. Please be sure your PC is free of viruses, and that sufficient memory is available. If ending these processes does not resolve the error, please reboot your PC. Please hit CONTROL-SHIFT-ESCAPE to bring up the task manager, click processes, and perform an end process on trose.exe and s. This is indicating that NProtect has already been loaded once and is still resident in memory. (No number shown) This means you're lagging.
Here you can find how to fixed them in that case wherein it happens to you without having a 3rd party application. Each of the case / error is associated to a certain problem.
When our game guard detects a program that is listed as threat on the cheats database, it will close your game client and a window with a Case Code / Error Code will open in your browser. MUGuard Errors, Detection Codes and Cases 1 MUGuard Errors, Detection Codes and Cases.