Currently many people are having a problem with the most recent patch. After starting the launcher the patch downloads and attempts to patch the game but errors near the end with an error "Source file was corrupted"and the game refuses to allow you to play the game. Many people have been told to download the whole game all over and even after doing that experience the same problem with the game client not working. Which is frustrating because it's a large file and no one wants to download 23gb+ without some kind of good results coming from it. But my friend in his wisdom found out how to resolve this error and was nice enough to provide me with a way of fixing my client before I rage uninstalled the game and quit Tera forever.
And because I know many of you will run into the same issue that I did I'm going to share the fix with you so you can get back into Tera Online and start playing again. Since I know not everyone uses the same version of windows I asked if my friend would provide two different versions of the files which he was very nice to do so.
64bit version: https://docs.google.com/file/d/0BwGeHg1m4YFLa0pqRU5Ua2tVanM/edit?usp=sharing
32bit version: https://docs.google.com/file/d/0BwGeHg1m4YFLdEpIYm1WTEpNdEU/edit?usp=sharing
The files inside these packages fix an issue with the splash image. If you used any custom modification's for custom splash images this would cause the client to get stuck and have problems but the above patches will fix that problem. You must close the launcher for this to work properly when you go to use it. The launcher will pass the part of the installation that it was getting stuck on after using the fix above which will allow you to get into game without a problem. If this works for you feel free to share it with friends you can follow me on google+ if you would like. Me and my friend will continue to provide valuable information for you Tera fans!