Due to a problem in the Intel® Quartus® Prime Pro Edition software version 20.2 and earlier, you may see the following error message during the Synthesis stage if your design instantiates ALTPLL IP Core and targets the Intel Arria® 10 Device.
Error(272000): Can't open DLL "cbx_altpll.dll"
Since ALTPLL IP Core does not support the Intel® Arria® 10 designs, it has been removed from future Intel® Quartus® Prime Pro Edition software version 20.3 and later. Use the IOPLL Intel FPGA IP Core instead.