Facing problem while simulating with HFSS

I need help to correct HFSS. When I start simulation, it gives message :
(1)Adaptive solution setup, process hf3d error: Matrix solver exception: out of memory, please verify Desired/Maximum RAM Limit setting
(2)Simulation completed with execution error on server: Local Machine.
I do not know what is matter? Please give ur valuable suggestions to correct the problem.

It means you either don't have enough RAM, or you have it set to use not enough RAM, and so the simulation stopped.