I've ran into this same error on a 740xd. In my case, there were bent pins in one of the NVME connectors on the system board. Ended up replacing the board and the error was gone. Hopefully its just a bad cable in your case.
Hello everyone, running into an error that I can't seem to fix. I have two units, and they are the full NVME 24-bay backplane configuration. I added NVME U.2 Dell branded SSDs and they all read fine and raid with zero issues. Loads into windows with zero issues. Bios and all firmware has been updated as of 2/27/2023 I verified the part numbers.  Riser 1 - MDDTD with NVME Card in slot 3 - PN W0DNK Riser 2 - RN1V2 with NVME Card in slot 4 - PN W0DNK  Riser 3 - DTTHJ - empty  Cables included - XN9T2 and X7MYJ    Slot bifurcation set to auto or default and still the same issue.    Is there a setting that I am missing ? [IMAGE]
Dell R740XD NVME PCIE Error