Internal Error: Sub-system: VPR20KMAIN, File: /quartus/fitter/vpr20k/altera_arch_common/altera_arch_place_delay.c, Line: 3906

Description

Due to a problem in the Quartus® Prime Pro edition software, you may see this internal error when compiling your design with physical synthesis enabled.

Resolution

To avoid this error, apply the following constraint in your .qsf (quartus settings file):

set_global_assignment -name ALLOW_REGISTER_RETIMING OFF

This problem is scheduled to be fixed in a future release of the Quartus Prime Pro edition software.