Internal Error: Sub-system: VPR20KMAIN, File: /quartus/fitter/vpr20k/bsyn_interface/bi_bsyn.cpp, Line: 171 - Internal Error: Sub-system: VPR20KMAIN, File: /quartus/fitter/vpr20k/bsyn_interface/bi_bsyn.cpp, Line: 171 Description Due to a problem in the Intel® Quartus® Prime Pro Edition software version 17.1 Update 1 and later, you may see this internal error during the fit stage. This problem only occurs when targeting Intel® Stratix® 10 devices. Resolution To work around this problem, add this constraint in the Quartus Setting File (.qsf) and recompile the project . set_global_assignment -name PHYSICAL_SHIFT_REGISTER_INFERENCE OFF Custom Fields values: ['novalue'] Troubleshooting 1507028560 False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software Pro'] novalue 17.1 ['Stratix® 10 FPGAs and SoCs'] ['novalue'] ['novalue'] ['novalue']