Hello, also the same here, I was in Adream and suddenly the game close showing me the OxE019101A in a pop-up window in the centre of the screen.

I close it and i start to double click on the knight online icon as normal to enter the game, so then the game window appears and does not allow me to press start, and the charging bar shows empty with this message on top: Checking version and preparing to launch the game.
Please I would like to know what's happening and the solution asap. because I have DC premium, oreads, valkyrie, menicias running without using it.
Thank you for reading...
So worried.