AttributeError: NullTranslationsBabel instance has no attribute 'isactive'

[admin]

How to Reproduce

While doing a GET operation on /logout, Trac issued an internal error.

(please provide additional details here)

Request parameters:

{}

User agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.0 Safari/537.36

System Information

Trac	1.0.1
Babel	1.3
Genshi	0.7 (without speedups)
Pygments	1.6
pysqlite	2.6.0
Python	2.7.8 (default, Jun 30 2014, 16:03:49) [MSC v.1500 32 bit (Intel)]
pytz	2014.7
setuptools	5.8
SQLite	3.6.21
jQuery	1.7.2

Enabled Plugins

tracpaththeme	1.0
tracthemeengine	2.2.1

Python Traceback

Traceback (most recent call last):
  File "c:\users\admini~1\appdata\local\temp\easy_install-ynvhvb\Trac-1.0.1-py2.7-win32.egg.tmp\trac\web\main.py", line 497, in _dispatch_request
    dispatcher.dispatch(req)
  File "c:\users\admini~1\appdata\local\temp\easy_install-ynvhvb\Trac-1.0.1-py2.7-win32.egg.tmp\trac\web\main.py", line 179, in dispatch
    chosen_handler)
  File "c:\users\admini~1\appdata\local\temp\easy_install-ynvhvb\Trac-1.0.1-py2.7-win32.egg.tmp\trac\web\main.py", line 325, in _pre_process_request
    chosen_handler = filter_.pre_process_request(req, chosen_handler)
  File "c:\users\admini~1\appdata\local\temp\easy_install-ynvhvb\Trac-1.0.1-py2.7-win32.egg.tmp\trac\versioncontrol\api.py", line 340, in pre_process_request
    if is_default(reponame):
  File "c:\users\admini~1\appdata\local\temp\easy_install-ynvhvb\Trac-1.0.1-py2.7-win32.egg.tmp\trac\versioncontrol\api.py", line 34, in is_default
    return not reponame or reponame in ('(default)', _('(default)'))
  File "c:\users\admini~1\appdata\local\temp\easy_install-ynvhvb\Trac-1.0.1-py2.7-win32.egg.tmp\trac\util\translation.py", line 195, in gettext
    if not self.isactive:
  File "c:\users\admini~1\appdata\local\temp\easy_install-ynvhvb\Trac-1.0.1-py2.7-win32.egg.tmp\trac\util\translation.py", line 190, in __getattr__
    return getattr(self.active, name)
AttributeError: NullTranslationsBabel instance has no attribute 'isactive'

[Jun Omae]

A duplicate of #10903. Try to downgrade Babel 0.9.6.