In the Quartus® Prime software version 16.1 Update 2 and earlier, you may see the ECOs editing mode greyed out in Chip Planner. This occurs because ECOs are not supported for Arria® 10 and Stratix® 10 devices.
Device Family: Intel® Arria® 10, Intel® Stratix® 10
Last Modified: April 13, 2017
Bug ID: FB: 152341;
This is scheduled to be supported in a future release of the Quartus Prime software.