Error in hfss simulation

During my simulation of CPW-fed monopole antenna centered at 2.45Ghz, the error occured. Please experter or experienced man check it for me. What does it mean? What should I do next step?
Thanks a lot!
cpwfed_monopole (D:/Program Files/project/)
glass_substrate
[error] Fast sweep setup, process abc3d : "WavePort1" mode 1 crosses cut-off in the specified fast sweep range. Consider splitting the sweep into multiple ranges. Use a port-only discrete sweep to locate the cut-off frequency.
[error] Simulation completed with execution error on server: Local Machine.

hi pst, see the file after my doing, hope it help.
i changed step and boud. condition.

Hi, it's so nice of you to solve my questions, and I will remember your name, cuongtran. :D