Internal Error: Sub-system: VPR20KMAIN, File: /quartus/fitter/vpr20k/altera_arch_common/altera_arch_re_network_routing_constraints.cpp, Line: 1437 - Internal Error: Sub-system: VPR20KMAIN, File: /quartus/fitter/vpr20k/altera_arch_common/altera_arch_re_network_routing_constraints.cpp, Line: 1437 Description Due to a problem in the Intel® Quartus® Prime Pro Edition software version 17.1 Update 2 and earlier, you may see this Internal Error in a fitter plan stage. Resolution This problem is fixed beginning with the Intel® Quartus® Prime Pro Edition software version 18.0 Update 1. Custom Fields values: ['novalue'] Troubleshooting 544608 False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software Pro'] 18.0.1 17.1.2 ['Stratix® 10 FPGAs and SoCs'] ['novalue'] ['novalue'] ['novalue']