Modelsim-Altera Simulation Error: Memory Allocation Failure

Hello everyone,

I am trying to run the gate level simulation for some VHDL code. I could run RTL simulation successfully. But I always get "Memory Allocation Failure" for gate level simulation. I have limited knowledge about quartus and VHDL and don't even know what can cause this error. I have been troubled by this problem for a week. Could someone please give me some help? Any idea is appreciated!

Thanks a lot!

David