The following exception is thrown when I access my repository page. It seems to be a compatibility issue with Mercurial 2.9?

** Unknown exception encountered with possibly-broken third-party extension redminehelper
** which supports versions unknown of Mercurial.
** Please disable redminehelper and try your action again.
** If that fixes the bug please report it to the extension author.
** Python 2.7.6 (default, Nov 10 2013, 19:24:24) [MSC v.1500 64 bit (AMD64)]
** Mercurial Distributed SCM (version 2.9)
** Extensions loaded: redminehelper
Traceback (most recent call last):
  File "hg", line 42, in 
  File "mercurial\dispatch.pyo", line 28, in run
  File "mercurial\dispatch.pyo", line 69, in dispatch
  File "mercurial\dispatch.pyo", line 134, in _runcatch
  File "mercurial\dispatch.pyo", line 806, in _dispatch
  File "mercurial\dispatch.pyo", line 586, in runcommand
  File "mercurial\dispatch.pyo", line 897, in _runcommand
  File "mercurial\dispatch.pyo", line 868, in checkargs
  File "mercurial\dispatch.pyo", line 803, in 
  File "mercurial\util.pyo", line 511, in check
  File "___/redmine-2.4.3/lib/redmine/scm/adapters/mercurial/redminehelper.py", line 175, in rhsummary
    _branches(ui, repo)
  File "___/redmine-2.4.3/lib/redmine/scm/adapters/mercurial/redminehelper.py", line 89, in _branches
    for t, n, r in sorted(iterbranches(), key=lambda e: e[2], reverse=True):
  File "___/redmine-2.4.3/lib/redmine/scm/adapters/mercurial/redminehelper.py", line 82, in iterbranches
    for t, n in repo.branchtags().iteritems():
  File "mercurial\repoview.pyo", line 199, in __getattr__
AttributeError: 'localrepository' object has no attribute 'branchtags'

Environment:
  Redmine version                2.4.3.stable
  Ruby version                   2.0.0-p353 (2013-11-22) [x64-mingw32]
  Rails version                  3.2.16
  Environment                    production
  Database adapter               PostgreSQL
SCM:
  Subversion                     1.8.5
  Mercurial                      2.9
  Git                            1.8.5.2
  Filesystem                     
Redmine plugins:
  no plugin installed