Internal Error: Sub-system: ATCL, File: /quartus/ccl/atcl/atcl_root.cpp, Line: 1022 - Internal Error: Sub-system: ATCL, File: /quartus/ccl/atcl/atcl_root.cpp, Line: 1022 Description Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 20.2 for Windows* 10, you may see this internal error when the fitter stage is being executed. The internal error description includes a DLL module that could not be found by the Windows* 10 operating system. e.g. ERROR: Can't load library: <Quartus_install_directory>\20.2\quartus\bin64\fitter_fdrgn.dll. The operating system reports the following error: The specified module could not be found. Resolution To work around this problem, install the Visual C Redistributable Packages for Visual Studio 2013 from the link . Custom Fields values: ['novalue'] Troubleshooting 00551642 False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software Pro'] novalue 20.2 ['Arria® 10 FPGAs and SoCs', 'Cyclone® 10 FPGAs', 'Stratix® 10 FPGAs and SoCs'] ['novalue'] ['novalue'] ['novalue']