After the maintenance (an assumption, weird things happen to me all the time) I cannot successfully launch the game. My launcher is displaying the following message: "Failed to update: Mabinogi is currently running." There is no instance of Mabinogi running in the background according to Task Manager. Additionally, I've installed/re-installed using different versions of the full client installer (sometimes trying to see if the primary launcher helped; to no avail). Using the primary launcher displays the following message: "Error retrieving local version, is the game installed?" Help?
That error message is caused by anything in your process list containing the name "Client".
As for error retrieving local version, this means the launcher is not accompanied by the game files, so it can't find the game.