When playing on the PC client, logging in informs me I have to update, but an update option is not available on Plarium Play. This means I cannot play on PC. I have uninstalled / installed the game with the same result.
I had to quit Plarium Play, not just the game to get it to download the update. You have to right-click the icon in the tray (it may be hidden) and tell it to exit, or if you're not sure how to do that, reboot.