How can i resolve the error in motor block in mobile robotics training library?

I am using MATLAB version - 2019b

I have downloaded mobile robotics training library. In that iam using motor block supported by VEX platform.

The following is the error after the run command

Error in 'lineFollow_PID_soln/Left Motor/Motor': Initialization commands cannot be evaluated.

Caused by:

• The "LTI system variable" parameter of the LTI block must be set to a valid LTI model.

In command window

Warning: Variable 'wheelMotorModel' originally saved as a idss cannot be instantiated as an object and will be read in

as a uint32.