ID:11981 File conversion is not allowed for internal active serial clock source that is greater than 12.5 MHz when you enable the CvP and non-volatile design security features

CAUSE: You attempted to convert a file with configuration via protocol (CvP) and design security features enabled for Arria V, Cyclone V, or Stratix V devices. However, this conversion is not allowed for internal active serial clock source that is greater than 12.5 MHz when you enable the CvP and non-volatile design security features.

ACTION: Use 12.5 MHz active serial clock source or lower when converting a file with CvP and design security features enabled for this device.