To resolve your issue, please follow these steps:
1. Please download and install the Service Pack 1 from the below link. Select your language and click on the "Download" button:
2. Select [vcredist_x86.exe] then click Next located at the bottom right-hand side of the page.
3. Download the installer (vcredist_x86) then run it. It's also fine to choose Run instead during the downloading process.
4. When you run the installer, if an issue occurs because the Microsoft Visual C++ 2008 Redistributable was previously installed, you will have the option to Repair the installation or remove it.
If you choose [Repair], skip Step 5 and 6. If you choose [Remove], proceed to Step 5 and 6 after the program is removed.
5. Once the screen below pops-up, click "Next"
6. Once the screen below pops-up, check [Agree] and click [Install].
7. When the installation is complete, navigate to [Control Panel] -> [Programs] and click on [Programs and Features].
8. In your Programs and Features installation list, Verify if Microsoft Visual C++ 2008 Redistributable- x86 9.0.30729.4148 version is installed properly.
9. Run Maplestory 2 and you should be able to launch the game successfully!
If this does not resolve your issue, please follow the steps for an alternate solution below.
1. Please change your current antivirus program with a different program OR you can run MapleStory 2 again after closing your antivirus program.
2. Navigate to [Start] and search [Run] in the search bar to open the command window.
3. Type in "msconfig" and search.
4. [System Configuration] window will open. Click on [Services] tab.
5. Check [Hide all Microsoft services].
6. Then from the service list, uncheck all the items that correspond to the manufacturer [INCA Internet co.ltd].
7. Run Maplestory 2 and launch the game successfully.
If the same error occurs even after Solution 1 and 2 are completed, please reinstall your Windows OS on your PC. (This issue can be resolved by Windows reinstallation without formatting.)