Due to a problem in the Intel® Quartus® Prime Pro Edition software, you will get the above error when porting a Stratix® 10 IOPLL design from older Intel® Quartus® Prime Pro Edition version to 17.1. IOPLL IP is supposed to force the IP regeneration to avoid an illegal setting. However, due to a problem in IOPLL, regeneration is optional.
Device Family: Intel® Stratix® 10
Intel Software: Quartus Prime Pro