I don't get any signal on the load, what am I missing? Shouldn't it amplify the input signal?

I have 50mA from the current mirror, the Vbe on Q10 and Q11 is around 0.75v

[![the differential amplifier](https://i.stack.imgur.com/7r1yQ.png)](https://i.stack.imgur.com/7r1yQ.png)