I tried to upgrade my Dell Precision M6800 memory with a couple of 8GB 1866MHz DDR3L "guaranteed compatible" modules and got error leds solid-blinking-solid which is explained in the manual as: "The memory modules are detected but has encountered an error". Does anyone know if that is always a sign of malfunctioning modules or can it give that error on some normal incompatibility for which there seems to be a separate code?