Without any other evidence I’d suspect a faulty dongle. You got thru the installation of Cubase and managed to enter the activation codes?!
Windows version single language because it was cheap? Buy cheap and you buy twice they say. Cubase isn’t cheap. Hm. Strange problem though. Try googling the problem as it APPEARS not what it occurs on (ie: the dongle) and see if it’s common thru, say, a graphics problem. Sample “distorted text in XXXX” program.
Also. Try changing you graphic resolution and see if it’s still there. I’m pretty sure there is an optimum (best) for Cubase. With luck if you change back to the resolution you started with the system can be tricked into normality.