ID:13103 Not allowed to move at least <number> registers because they are connected to SERDES

CAUSE: You attempted to optimize netlists by directing the Quartus Prime software to perform gate-level register retiming. However, the Quartus Prime software cannot move the specified number of registers because they are fed by the data-out port on a SERDES receiver, or a data-in port on a SERDES transmitter. The number of registers reported in this message may be lower than the actual number of registers connected to SERDES, because some registers may not be allowed to be moved for other reasons.

ACTION: If you want to allow the Quartus Prime software to move these registers, set the Netlist Optimizations logic option to Always Allow. Otherwise, no action is required.