I tried to partition my Disk but it failed with this message:
I have tried First Aid under Recovery and it said the First Aid is completed. However, the partition still failed. What should I do?
My specs:
Macbook pro 2015 Retina model.
8G RAM 256G SSD.
macOS Sierra
[Edit]
Under Recovery, I can only run First Aid on the disk not on the "Macintosh HD" volume because it is greyed out. Another thing to mention is I installed rEFInd on my Mac as I was planning to install Ubuntu alongside macOS. Is any of this relevant to my problem?