Problem simulating 2-bit counter with OrCAD
You need to initialize the flops, otherwise their starting state is unknown (this is showing as the red traces in the sim.)
With successive clocks, unknown continues to propagate to unknown, even though we know that in a real circuit the flip-flop states would resolve themselves one way or another.
Connect the flip-flop CLRn signals to a reset signal that pulses low at the beginning of the sim. This ensures a starting state of [0,0] which will then count up as you expect.
Logic simulations are picky that way; and seems like OrCAD pSPICE is also picky (or at least, the 74HC74 model is picky.) This is not a bad thing really, it ensures you've thought about your design.