Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 17.1 Update 1 and earlier, you might see the following internal error during compilation of an Intel® Stratix® 10 FPGA design containing DUPLICATE_ATOM assignments.
Internal Error: Sub-system: CDB_ATOM, File: /quartus/db/cdb_atom/cdb_atom_sys.cpp, Line: 2682
Fanout can only be added to atom in same netlist.
The problem occurs when the "-from" node and "-to" node specified in the DUPLICATE_ATOM assignment are in two different design partitions.
To work around this problem, ensure that "-from" node and "-to" nodes specified in a DUPLICATE_ATOM assignment are within the same design partition.