Internal Error: Sub-system: OPT, File: /quartus/synth/opt/opt_dsp_wys.cpp, Line: 1688 - Internal Error: Sub-system: OPT, File: /quartus/synth/opt/opt_dsp_wys.cpp, Line: 1688 Description Due to a problem in the Quartus® II software version 13.1 Update 4 and earlier, you may see this error when compiling a FIR Compiler II design. Resolution To work around this problem, download and install patch 4.47 from the links below. You must install the Quartus II software version 13.1 Update 4 before installing this patch. Download the version 13.1.4 patch 4.47 for Windows (.exe) Download the version 13.1.4 patch 4.47 for Linux (.run) Download the Readme for the Quartus II software version 13.1.4 patch 4.47 (.txt) This problem is scheduled to be fixed in a future release of the Quartus II software. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['FPGA Dev Tools Quartus II Software'] 14.0 novalue ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']