Initialization error while using ex_simrf_dc in Simulink RF toolbox

Hi,

I am new to simulink and I want to model a RF communication system. To understand an example, I tried simulating this: http://www.mathworks.in/help/simrf/ug/modeling-a-direct-conversion-receiver.html#bskdxme When I start the simulation, I get a list of errors which say " Initialization commands cannot be evaluated.". This is the error for: 1.Amplifier 2.Amplifier 1 3.Amplifier 2 4.Mixer_I 5.Mixer_Q 6.lna

Help me understand what this error means and how to tackle it. Thanks!