I had this problem and lots of other people did too. The blue box shows up with nexon korea and nexon america at the bootom and just crashes/closed everytime.

First you need to turn off your firewall. I know this sounds dodge your firewall is blocking the game to start. Next close steam completely and i am not talking about just clicking X at the top right because then it still runs in the background. You need to click steam in the top left hand corner then Exit, this will fully close it. Next find your steam launcher, not a shortcut but the Steam.exe. You can find this in C:\Program Files (x86)\Steam. Make sure it is Steam.exe not any of the other one that look similar like steamerrorreporter.exe. Once you found it right click it and run it as Administrator. Once steam has launched try playing Riders of Icarus.

MAKE SURE YOU TURN YOUR FIREWALL ON AFTER!!!

If you run into issues with running Ridiers of Icarus and receive any error related to Microsoft Visual C++ Redistributable Package, downloading these files should resolve your issue. Below you will find four separate links to the Microsoft website containing additional information for these packages, which you will need to download and install, as this will ensure all of the proper packages are installed.

Microsoft Visual C++ 2010 Redistributable Package (x86)
https://www.microsoft.com/en-us/download/details.aspx?id=5555

Microsoft Visual C++ 2010 SP1 Redistributable Package (x86)
https://www.microsoft.com/en-us/download/details.aspx?id=8328

Microsoft Visual C++ 2010 Redistributable Package (x64)
https://www.microsoft.com/en-us/download/details.aspx?id=14632

Microsoft Visual C++ 2010 SP1 Redistributable Package (x64)
https://www.microsoft.com/en-us/download/details.aspx?id=13523

This error occurs when you try to lauch. It is a problem with your computer not Riders of Icarus but it is still easy to fix. This fix is for Windows computers only. I don't think Macs or Linx computers will have this error. Everybody will have different runtime errors becuase people have differnet software on their computers. A helpful link is https://support.microsoft.com/en-us/kb/929135 because it explains a bit more about runtime errors and how to fix them.

First press the windows key and 'R' key at the same time to open the run prompt. Type into the run prompt: appwiz.cpl then press enter. Find all the installations relating to the Microsoft Visual C++ Runtime and uninstall them one by one. Download and re-install the previosly removed runetime libraies. Clean boot your computer then check to see if it will run. To enter a clean boot state, type msconfig in start search and hit Enter to open the System Configuration Utility. Click the General tab, and then click Selective Startup. Clear the Load Startup Items check box. Finally, ensure that Load System Services and Use Original boot configuration are checked. If it does work, then you need only isolate the service that is conflicting with the launcher or go straight into "System Configuration", click on the services tab, click on hide MS services, and look to see if you have "Driver Support AO Service" there, if so, this is likely your culprit. Re-Installing the MS Visual C++ Runtime stuff as per the instructions in the guide wouldn't hurt either.

I would like to thank Subotai for helping me and finding the fix. If you need any extra help with this you should ask him before me because i have limited knowledge about this.
https://steamhost.cn/steamcommunity_com/profiles/76561198034779285

This one is very simple and quick to fix.

All you have to do is delete the "Nexon Guard Folder" located here: C:\Nexon\Library\icarus\appdata

This game kills your CPU. This bug will not effect everybody but their is a temporary fix.

First open task manager (Ctrl+Alt+Del) and look for 'Nexon Security' and end it. Nexon Security takes up to 20% or even 30% of your CPU so it is killing it. It does reduce the CPU usage which means you will have less FPS drops and general higher FPS. Do this at your own risk. I don't know what the Nexon Security does at the moment but this is a fix.

This is a fix for some glitchy graphics problems that I know of. Go into your graphics card control panel, manage 3D settings, look for Antialiasing Mode and make sure it's set to application controlled. Other settings may need to be application controlled also.

I would like to thank Silly Bunny for helping me and finding the fix. If you need any extra help with this you should ask him before me because i have limited knowledge about this.
https://steamhost.cn/steamcommunity_com/profiles/76561197967315648

This is a weird bug. Some times the game doesn't show your correct monitor resolution. This method will not work for everybody because some don't have the folder, I don't know/understand why this is.

If your monitor resolution is 1920x1080 and you can't find it in the settings try going to C:\Users\UserName\Documents\ICARUS\USER\UserConFig\GraphicOption.XML and open it with wordpad or notepad++. Next change it to your resolution, for example <screensize screenwidth="1920" screenheight="1080"/>. If this doesn't work right click the GraphicOption.XML file and choose properties. After mark it as Read-only and then click ok. Run the game and it should work.

This bug is not much of a problem as it still allows you to play. This bug occurs when trying to quit the game and it will just show a black screen.

If you are playing on borderless windowed mode then it is simple. To close it fully all you have to do it go to your task manager (Ctrl+Alt+Del) and then look for the process called Launch. Once you have found it click 'End Task' and it will close it. You may have to do this everytime you exit the game.

If you are playing on fullscreen you must open task manager BEFORE opening the game. When you want to close the game alt+tab to open it. You will not be able to see it but it is there. Press down once then delete to close the game.

I would like to thank KarKer for helping me and finding the fix. If you need any extra help with this you should ask him before me because i have limited knowledge about this.
https://steamhost.cn/steamcommunity_com/profiles/76561198044345034

If you have any bugs that I have not mentioned in this guide, any bugs that i have mentioned that you have new or alterative fixes or need addition help fixing bugs feel free to add me on steam.

I play on EU if anybody want to join my guild or just play.
World - Koroshimo (EU)
IGN - Gazder (Priest)
Guild - Pokemon
Discord - https://discord.gg/FChSKx7

Their is a few bugs that i know exist but don't have any fix for them:

• Authorization timeout
  
• NXGuard (code:276)
  
• Cursor not appearing
  
• Crash when changing resolution on fullscreen
  
• Freeze after clicking 'Start Game'
  
• Alt-Tab while in windowed mode creates graphical issues
  
• Invisible players
  
• Can't change lanuage