Due to a problem in the Intel® Quartus® Prime Pro edition software version 20.1, you may see this internal error during the fitter stage.This problem only occurs in designs targeting Intel® Stratix® 10 devices and running post-route physical synthesis.
Device Family: Intel® Stratix® 10
Intel Software: Quartus Prime Pro
Last Modified: July 10, 2020
Version Found: v20.1
Version Fixed: v20.3
Bug ID: 1507975858