HFS partition fails to mount on Mac after being mounted on Ubuntu I recently followed the instructions here to mount an Apple-formatted HFS external drive on Ubuntu. I transferred the files I needed, then unmounted the drive. Now the drive won't mount in OSX. In Disk Utility, the volume (top level) and partition (bottom level) for the external hard drive show up, but the partition will not mount. First Aid on the top level completes without error, but running First Aid on the partition level fails.

What could be preventing me from mounting the drive after following those instructions?

Any help would be greatly appreciated!

$ diskutil verifyVolume disk2s2
Started file system verification on disk2s2 WD My Passport
Verifying file system
Volume is already unmounted
Performing fsck_hfs -fn -x /dev/rdisk2s2
File system check exit code is 8
Restoring the original state found as unmounted
Error: -69845: File system verify or repair failed
Underlying error: 8: Exec format error
I solved the issue by running sudo fsck.hfsplus /dev/sdx# from my Ubuntu machine. My external drive can now connect to both my Ubunutu and Mac machines.