Attempting to run z3 on my Solaris test box before rolling to production and getting the error below

root@solaris-test:~# z3 status
backup status for None@zfs-auto-snap:daily* on moose1/z3-backup/
bad property list: invalid property 'written'
For more info, run: zfs help list
Traceback (most recent call last):
File "/usr/bin/z3", line 9, in
load_entry_point('z3==0.2.0', 'console_scripts', 'z3')()
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 53, in wrapper
return func(*args, **kwargs)
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 596, in main
filesystem=args.filesystem)
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 485, in list_snapshots
for s3_snap, z_snap in pair_manager.list():
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 283, in list
for z_snap in self.zfs_manager.list():
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 229, in list
return self._snapshots.values()
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 25, in cacheing_wrapper
val = func(self, *a, **kwa)
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 226, in _snapshots
return self._build_snapshots(self._fs_name)
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 207, in _build_snapshots
fs_snaps = self._parse_snapshots().get(fs_name, {})
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 184, in _parse_snapshots
snap = self._list_snapshots()
File "/usr/lib/python2.7/site-packages/z3/snap.py", line 174, in _list_snapshots
'name,used,refer,mountpoint,written'])
File "/usr/lib/python2.7/subprocess.py", line 219, in check_output
raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command '['zfs', 'list', '-Ht', 'snap', '-o', 'name,used,refer,mountpoint,written']' returned non-zero exit status 2

It would appear the issue is centered arround the "written" argument provided.

root@solaris-test:~# zfs list -Ht snap -o name,used,refer,mountpoint,written
bad property list: invalid property 'written'

Remove the "written" argument and the command produces the following argument

root@solaris-test:~# zfs list -Ht snap -o name,used,refer,mountpoint
rpool/ROOT/solaris@install 59.9M 2.55G -
rpool/ROOT/solaris@2019-05-22-20:48:38-219 76.1M 2.63G -
rpool/ROOT/solaris/var@install 140M 314M -
rpool/ROOT/solaris/var@2019-05-22-20:48:38-219 29.9M 204M -