A design compiled in the Quartus II software version 10.1 cannot be directly recompiled in version 11.0, for speeds greater than 500 MHz.
Type: Answers, Errata
Area: EMIF, Intellectual Property
The workaround for this issue is to load the
generated by the version 10.1 MegaWizard Plug-In Manager into the
version 11.0 MegaWizard Plug-In Manager and regenerate the IP core
in version 11.0.