2 L2 Clients in Windows mode?

Ive just come to load my 2 buffers in 2 L2 Client windows and as i open the second L2 Client the 1st one critical errors.

Whats with this? Have i spent most of C3 leveling a buffer i wont be able to use? Have i wasted months of payment fee's to only be able to run 1 client per pc?

Please tell me i'm wrong

Did this just start with the c4 client? I hope not, being able to box a prophet is so much of a difference that it is unbelievable.

If this is the case then you can stick a fork in me. :mad:

(Still stuck at work and can't test yet)