During MAP on my design, I receive the following fatal error:
One solution can be to place XBLKNM constraints on the error(s) in question:
However, if doing this still does not resolve the error, it might be an issue with MapLib inserting the phase calibration circuit for the MMCM in V6 devices.
There is an environment variable that disables this insertion, which would prevent this optimization from taking place.
You will need to re-validate the design to ensure that it works as expected.