Login Error Due to Corrupted Files

I have tried to launch MxO through Station Launcher and when I do, I get the following error message upon the character loading screen...

Failure due to corrupted files. Run a virus scan, then retry with the "Full System Check". If the problem persists, click the Support button in the launcher.

I have run a virus scan with AVG, and nothing. When I try and click the Support button with the MxO launcher, it opens a new window in my browser and says, "Illigal parameter".

Help please!