Error using FIR Compiler v9.1

I'm using FIR Compiler v9.1 to generate a FIR filter. It doesn't seem to be generating the file filtername_st.v that is needed for synthesis and creating the .vho simulation model. The error I get is as follows:

"Error: Node instance "fircore" instantiates undefined entity "filtername_st" File".

If I select the option to generate the simulation model, this error appears while the megawizard is creating the filter and does not finish. If I don't select the option, it creates the filter, but when I try to synthesize the error appears. It looks like entity filtername_st is instantiated in filtername_ast.

Thanks for anyone's help.