I'm having problems mounting ext4 partitions(inside a LUKS partition) in external drives. The drives are fine, there is no problem whatsoever with the drives and no filesystem corruption. This happened since a recent automatic system upgrade, and a manual upgrade to kernel 3.12.0. It goes like this: I plug in the external drive Passphrase is asked for luks device luks partition correctly unlocked/opened Instead of proceding with mounting the now exposed ext4 partition there's a pop-up saying: "the unlocked device does not have a recognizable filesystem on it". Same happens in this case: $ gvfs-mount -d /dev/sdc2 Enter a passphrase to unlock the volume The passphrase is needed to access encrypted data on WDC WD250... (250 GB Hard Disk). Password: Error mounting /dev/sdc2: The unlocked device does not have a recognizable file system on it Doing a manual sudo mount /dev/dm-1 /mnt/testfolder works with no errors and there is no problem with the filesystem (fscked). Also there doesn’t seem to be anything useful written to dmesg when this happens. What gives?