Help for HFSS Analysis setup

Hi anyone.
I want to know what's the meaning of this message in hfss 11(for a waveguide and a microstrip antenna array this error was occurred!):
Solution setup 'setup1':Given the specified frequency and and model dimensions,an extremely large mesh will be required to produce an accurate solution.Your model and/or frequency units may be set incorrectly.
thanks

I would think that this shows up as a warning and not an error ?

In any case, you check the frequency range you are solving for and the dimensions of your model. You can think of this message as occurring when you solve something like a 100 metre long model at 80 GHz, with a fine mesh everywhere.

Can you post back with the maximum dimension of your design and the solution frequency ?

The solution frequency is 20 GHz and the maximum number of passes is 9 and the maximum delta S is 0.001
The surprising point is that this is an old solved problem!( 20 GHz waveguide combiner) that has been solved with a 128 MB ram at 30 min! But,with my computer(4 GB ram) it's not! I'm confused!

That is strange.

Is it is the same as this document [ http://www0.egr.uh.edu/courses/ece/E.../waveguide.pdf ] ?

Yes it is!
Help me! plz...!

check the attached file.

wg_combiner.zip