The old launcher says 'Download Cancelled' after a minute or two - it's broken.
The new launch pad lets me into game, which then crashes because it's not downloaded enough files. It doesn't seem to want to patch the files I have, but instead to download the entire 13.64GB.
Hope Velious is worth the wait - I won't be playing today...
EU Launcher - An Unknown Error Has Occurred
... if only!!!
Please give our LaunchPad for Everquest II a shot instead. When installing it, select your existing EQ2 folder to avoid a hefty re-download of the game.