Hello! i had already installed a crucial 4gb ddr4 2400 dimm my pc runs fine ,i just bought another one and put it in, and then mobo flashes this led errors.I put the new dimm in all slots alone pc doesnt post ,but it works again with the previous ,the modules are the same model. my mobo is MSI H110M PRO VH .
Make sure your BIOS/UEFI memory & CPU settings are set to Auto or Defaults since the new module may not be able to handle any custom settings. You could also try clearing the BIOS/UEFI settings and setting them all back to defaults just in case something odd happened with them. If these are set to Auto/Defaults, then it sounds like you may have received a defective module. You could chat with Crucial Support to verify you did receive the correct module for your system. I don't think you will have any problem getting it exchanged.