Unable to simulate in modelsim

Hi,

i'm using quartus tool 11.0 with modelsim version 6.4d designer edition. After synthesis of the design in quartus I open modelsim from the tool itself, after that modelsim complies all the library wich is automatically invoked. But when I try to simulate the file it s showing error as below, so what may be the reason.

# Error: setupTask: Could not find task '"Greenlight Compile"'.# # Error: # # Error: Unable to run task : Greenlight Flow