I have been trying to figure this error out, and have found no answer. Basic background of issue: From one instance to another, my Macbook went from working fine to unusable. My hard drive is unbootable, and I have tried everything to salvage my information inside. I bought a USB hard drive adapter to see if it would boot up this way, but Disk Utilities does not let me mount the drive although it reads it. Based on the Apple Hardware Test, this error is related to memory. I have 8GB of RAM, so I don't know how, or if, it is related to the hard drive not booting. Any help would be appreciated!!