I had this problem under macos 10.12.1(Sierra), after some research, this might be caused by a long-running fsck process that preventing the disk utils from loading the content, you might want to do this:
in terminal
ps -ef | grep fsck
$ ps -ef|grep fs
0 55 1 0 3:39PM ?? 0:03.45 /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/FSEvent s.framework/Versions/A/Support/fseventsd
0 110 1 0 3:39PM ?? 0:00.02 autofsd
0 126 1 0 3:39PM ?? 0:01.44 /usr/sbin/cfprefsd daemon
501 326 1 0 3:39PM ?? 0:01.47 /usr/sbin/cfprefsd agent
0 14893 86 0 4:45PM ?? 1:41.64 /System/Library/Filesystems/hfs.fs/Contents/Resources/./fsck_hfs -y /dev/disk2s2
501 18726 3828 0 5:02PM ttys000 0:00.00 grep fs
Then you can sudo kill that process, 14893 in my case. Once the fsck process is killed, the disk utils should load correctly.
This might signal that your volume might be corrupted, so it's better run fsck manually, or re-format the volume.