I am attempting to at least get my MP up Sierra or High Sierra. Not sure if you can jump from 10.11 to 10.13. I have downloaded the 10.12.6 os. Tried running the patch Dosdude provides.. I see you need to turn off System Integrity Protection before you can run his patch. I cannot get my MP to boot in recovery mode to turn this off.. It keeps saying I shut down to fix a problem, but will not go into recovery mode..