Navigate to your Everquest Titanium directory. Run the file "Launch Titanium.bat"
If you haven't already downloaded the new patch files, you will need to do so
here. You won't have launch titanium.bat until you do.
If you've already done these steps and still get the same error, navigate to your Everquest folder and be sure you have eqgame.exe - if you do not, you may need to re-install. Make sure you're in the correct directory! You'd be surprised how often people go the wrong folder and wonder why nothing works!