Unrecognized function or variable

I have an s-function called smn_sfunc_gam_mpass_epsposdef.mexw64'.

When I try to simulate the s-function in Simulink, I am getting an error:

"Unrecognized function or variable 'smn_sfunc_gam_mpass_epsposdef'"

I am giving the command in the same folder as that of the s-function, so path should not be an issue.

Any idea what's going on?

Thanks.

[Steven Lord]

This may seem like an obvious question, but are you running Simulink on a 64-bit version of Windows? Files with the .mexw64 extension only run on 64-bit Windows.

[Suvo Ganguli]

Yes, I am using 64 bit Windows.