I'm kind of stuck with a 30GB partition on the hard drive of my MBP that I cannot regain. This is what happened:
I used boot camp to try to install Win 10 on a partition
Once it rebooted into Win10 setup, it failed to install the system on the partition
- I tried to use Boot Camp Assistant to remove the partition but I'm getting this message:
The startup disk cannot be partitioned or restored to a single partition.
Then, I used disk utility to try to merge my main partition with the mentioned above but it won't let me remove it (I tried from recovery mode with the same results)
I'm using macOS Sierra 10.12.3 on my Late 2015 15" MBP.