What Matlab/Simulink version are you using?
Have you been able to use the import previously?
Finally, are you launching Matlab from the Amesim menu? This helps to configure Matlab properly.
The main thing is to have a MATLAB environment variable pointing to your Matlab installation folder.
MATLAB Version 9.0 (R2016a)
Simulink Version 8.7 (R2016a)
I haven't been able to import it previously using the amesim component (from LMS AMESim interfaces library) however I am able to run it when I use a S function (from user-defined functions library). However now I'm running to issues when I want to select my solver, so thats why I want to use your built in S-function to carry the work I'm doing.
I have checked that my MATLAB variable is set to the installation folder.