And same issue here. It started just this evening as I was able to play this afternoon it and the last few weeks without a problem (well not without a problem, since I had the blank screen error and had to close steams after login but before game start as a workaround).

There really a few issues with this game and steam (was able to pay via credit card 6 months ago, but after rejoining the game, I had to switch to payment via Steam, although the credit card option was still shown in my mogry station).
The payment issue and the black screen issues were solveable but this now is gamebraking (and actually is reducing my paid gametime -.-)

I hope this gets fixed soon.