fft megacore core giving all HI-Z to all output signals

I added a 512 point fft core from library to my code. I am trying to simulate it by using the testbench in ModelSim. I am using Quartus II Lite for now. The code compiles fine. However, all outputs from core are HI-Z as in attachment despite correct inputs given to core form test bench. I do not even get sink_ready signal from FFT core.

I will appreciate any help.