Trying to promote a client to a replica and it's failing with:

Upgrading IPA:. Estimated time: 1 minute 30 seconds
  [1/9]: stopping directory server
  [2/9]: saving configuration
  [3/9]: disabling listeners
  [4/9]: enabling DS global lock
  [5/9]: starting directory server
  [6/9]: upgrading server
  [7/9]: stopping directory server
  [8/9]: restoring configuration
  [9/9]: starting directory server
Done.
Restarting the KDC
Your system may be partly configured.
Run /usr/sbin/ipa-server-install --uninstall to clean up.

ipa.ipapython.install.cli.install_tool(CompatServerReplicaInstall): ERROR    406 Client Error: Failed to validate message: No recipient matched the provided key["Failed: [ValueError('Decryption failed.',)]"]
ipa.ipapython.install.cli.install_tool(CompatServerReplicaInstall): ERROR    The ipa-replica-install command failed. See /var/log/ipareplica-install.log for more information

The replica-install log:

2017-10-04T07:22:06Z DEBUG Restarting the KDC
2017-10-04T07:22:06Z DEBUG Starting external process
2017-10-04T07:22:06Z DEBUG args=/bin/systemctl restart krb5kdc.service
2017-10-04T07:22:06Z DEBUG Process finished, return code=0
2017-10-04T07:22:06Z DEBUG stdout=
2017-10-04T07:22:06Z DEBUG stderr=
2017-10-04T07:22:06Z DEBUG Starting external process
2017-10-04T07:22:06Z DEBUG args=/bin/systemctl is-active krb5kdc.service
2017-10-04T07:22:06Z DEBUG Process finished, return code=0
2017-10-04T07:22:06Z DEBUG stdout=active

2017-10-04T07:22:06Z DEBUG stderr=
2017-10-04T07:22:06Z DEBUG   File "/usr/lib/python2.7/site-packages/ipapython/admintool.py", line 172, in execute
    return_value = self.run()
  File "/usr/lib/python2.7/site-packages/ipapython/install/cli.py", line 333, in run
    cfgr.run()
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 368, in run
    self.execute()
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 392, in execute
    for _nothing in self._executor():
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 434, in __runner
    exc_handler(exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 463, in _handle_execute_exception
    self._handle_exception(exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 453, in _handle_exception
    six.reraise(*exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 424, in __runner
    step()
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 421, in <lambda>
    step = lambda: next(self.__gen)
  File "/usr/lib/python2.7/site-packages/ipapython/install/util.py", line 81, in run_generator_with_yield_from
    six.reraise(*exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/util.py", line 59, in run_generator_with_yield_from
    value = gen.send(prev_value)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 658, in _configure
    next(executor)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 434, in __runner
    exc_handler(exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 463, in _handle_execute_exception
    self._handle_exception(exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 521, in _handle_exception
    self.__parent._handle_exception(exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 453, in _handle_exception
    six.reraise(*exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 518, in _handle_exception
    super(ComponentBase, self)._handle_exception(exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 453, in _handle_exception
    six.reraise(*exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 424, in __runner
    step()
  File "/usr/lib/python2.7/site-packages/ipapython/install/core.py", line 421, in <lambda>
    step = lambda: next(self.__gen)
  File "/usr/lib/python2.7/site-packages/ipapython/install/util.py", line 81, in run_generator_with_yield_from
    six.reraise(*exc_info)
  File "/usr/lib/python2.7/site-packages/ipapython/install/util.py", line 59, in run_generator_with_yield_from
    value = gen.send(prev_value)
  File "/usr/lib/python2.7/site-packages/ipapython/install/common.py", line 63, in _install
    for _nothing in self._installer(self.parent):
  File "/usr/lib/python2.7/site-packages/ipaserver/install/server/__init__.py", line 617, in main
    replica_install(self)
  File "/usr/lib/python2.7/site-packages/ipaserver/install/server/replicainstall.py", line 386, in decorated
    func(installer)
  File "/usr/lib/python2.7/site-packages/ipaserver/install/server/replicainstall.py", line 1477, in install
    custodia.import_dm_password(config.master_host_name)
  File "/usr/lib/python2.7/site-packages/ipaserver/install/custodiainstance.py", line 124, in import_dm_password
    cli.fetch_key('dm/DMHash')
  File "/usr/lib/python2.7/site-packages/ipaserver/secrets/client.py", line 101, in fetch_key
    r.raise_for_status()
  File "/usr/lib/python2.7/site-packages/requests/models.py", line 834, in raise_for_status
    raise HTTPError(http_error_msg, response=self)

2017-10-04T07:22:06Z DEBUG The ipa-replica-install command failed, exception: HTTPError: 406 Client Error: Failed to validate message: No recipient matched the provided key["Failed: [ValueError('Decryption failed.',)]"]
2017-10-04T07:22:06Z ERROR 406 Client Error: Failed to validate message: No recipient matched the provided key["Failed: [ValueError('Decryption failed.',)]"]
2017-10-04T07:22:06Z ERROR The ipa-replica-install command failed. See /var/log/ipareplica-install.log for more information

Not really sure where to look for what is causing the error from here. Any help appreciated.