Which Tool versions have you used?
Have you tried to simulate the design example ?
Not able to replicate the simulation error mentioned.
I have used the design example, Modelsim 10.6C and followed the steps from link below.
Attached the image for reference.
Let me know if this has helped resolve the issue you are facing or if you need any further assistance.
Anand Raj Shankar
(This message was posted on behalf of Intel Corporation)