fsck.ocfs2: Unsupported feature(s) found on all journals

[rascalDan]

Whilst attempting to run fsck.ocfs2 -f -P /dev/drbd/by-res/store:

fsck.ocfs2 1.8.8
Checking OCFS2 filesystem in /dev/drbd/by-res/store:
  Label:              store
  UUID:               21ED2443E640434B971B15D22AB2490F
  Number of blocks:   196601991
  Block size:         4096
  Number of clusters: 196601991
  Cluster size:       4096
  Number of slots:    2

journal recovery: Unsupported feature(s) found on all journals.  Please upgrade to the latest version of fsck.ocfs2
fsck saw unrecoverable errors in the journal files and will not continue.

I'm not sure I fully understand the feature logic in the code, but am I right in saying that these features:

Feature Compat: 3 backup-super strict-journal-super
Feature Incompat: 47056 sparse extended-slotmap userspace-stack inline-data xattr indexed-dirs refcount discontig-bg append-dio
Tunefs Incomplete: 0 
Feature RO compat: 1 unwritten

mean that unwritten is only supported for read-only operations, and that if the journal (and file system feature flags?) have this enabled, then it cannot continue?

I've tried disabling the feature, but that fails because there's an unsupported feature.

Which has left me at a bit of dead end... several file systems with that feature enabled that I can't run fsck on. Any suggestions on what I can/should do... or point out the misunderstanding I've made above. Thanks.