Most of the issues that we have seen attributed to this error message have been due to a firewall. If you are receiving this error message, we suggest trying the following steps.

First, try disabling any and all firewalls that you have running on your machine to see if this alleviates the issue.

If you are using Comodo Internet Security please try the following:

• Modify your Heuristics setting.  Setting Heuristics to Low or Off is the best option
• Deactivate Defense+.  To do this, open go to the Comodo Firewall -> Defense+ -> Advanced -> Defense+ Settings -> Check the box for "Deactivate the Defense+ Permanently", and then reboot to apply the changes. 
• If the issue persists please try uninstalling Comodo completely.

If you are using Windows Vista or Windows 7 please disable User Account Controls by following these instructions here.

If the issue persists, you'll need to adjust your firewall exceptions to allow exceptions for certain game files.  Specific instructions for this can typically be found on the respective manufacturers' websites. The process will vary by manufacturer.

If you are playing Aion please add these exceptions:

AION.bin, GameGuard.des, GameMon.Des, npggNT.des and NCLauncher.exe

The default locations for each file are as follows:

   "C:\Program Files\NCSoft\Aion\bin32\AION.bin"
   "C:\Program Files\NCSoft\Aion\bin32\GameGuard.des"
   "C:\Program Files\NCSoft\Aion\bin32\GameGuard\GameMon.des"
   "C:\Program Files\NCSoft\Aion\bin32\GameGuard\npggNT.des"
   "C:\Program Files\NCSoft\Launcher\NCLauncher.exe"

If you are playing Lineage II please add these exceptions:

LineageII.exe, L2.bin, GameGuard.Des and GameMon. Des.

The default locations for each file are as follows:

"C:\Program Files\Lineage II\LineageII.exe"
"C:\Program Files\Lineage II\system\l2.bin"
"C:\Program Files\Lineage II\system\GameGuard.des"
"C:\Program Files\Lineage II\system\GameGuard\GameMon.des"

If you are still receiving this error message after trying these steps, you should make sure that you have no third party applications attached to the Lineage II program.

If after trying all of these adjustments the issue still occurs please try temporarily uninstalling your security software completely.  If this resolves the issue then please contact the software manufacturer for instructions on how to configure it correctly if you wish to reinstall it.