Disk Utility not letting me Partition Disk A bit of background before I start. I'm trying to install Ubuntu onto my Macbook Pro and so far I've stumbled into a bit of a roadblock. I've also already installed Windows 10 with Bootcamp, I'm not sure if that makes a difference.

The issue I'm having is whenever I try to create the partition using Disk Utility it seems to get stuck at "Preparing to partition disk" no matter how long I wait for it. It really doesn't seem to matter what format I make the new partition, I still end up getting the same issue.

If anybody has any idea why this is happening or what I can do to fix it would be greatly appreciated.
In Disk Utility, select the drive that you wish to partition, but select Repair in the bar with the options. Then, click Repair Disk Permissions in the bottom right. Repairing Disk Permissions isn't guaranteed to fix your problem, but it's a great start.