problem while running a comsol mesh file,which is saved in comsol software as M-file

Dear sir, I am getting error while running a comsol modeled file. Comsol has the option to save a model as M-file. While i am try to run the model in matlab (drag and drop it in control window) i am getting the error:

run('D:\Users\sudhakar\Desktop\New folder\a.m') ??? Undefined variable "ModelUtil" or class "ModelUtil.create".

Error in ==> a at 10 model = ModelUtil.create('Model');

Error in ==> run at 57 evalin('caller', [s ';']);

??? Undefined variable "ModelUtil" or class "ModelUtil.create".

Error in ==> a at 10 model = ModelUtil.create('a');

Pls help me in this perspective