升级到 Flask 0.10 后，我收到此错误：
flask.debughelpers.UnexpectedUnicodeError
UnexpectedUnicodeError: A byte string with non-ASCII data was passed to the session system which can only store unicode strings. Consider base64 encoding your string (String was 'iB\rOU#\xf7BO\x08^\xa6\xd1)v\xad')
Traceback (most recent call last)
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/app.py", line 1479, in full_dispatch_request
response = self.process_response(response)
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/app.py", line 1693, in process_response
self.save_session(ctx.session, response)
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/app.py", line 837, in save_session
return self.session_interface.save_session(self, session, response)
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/sessions.py", line 321, in save_session
val = self.get_signing_serializer(app).dumps(dict(session))
File "/srv/www/li/venv/lib/python2.7/site-packages/itsdangerous.py", line 471, in dumps
return self.make_signer(salt).sign(self.dump_payload(obj))
File "/srv/www/li/venv/lib/python2.7/site-packages/itsdangerous.py", line 676, in dump_payload
json = super(URLSafeSerializerMixin, self).dump_payload(obj)
File "/srv/www/li/venv/lib/python2.7/site-packages/itsdangerous.py", line 454, in dump_payload
return self.serializer.dumps(obj)
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/sessions.py", line 82, in dumps
return json.dumps(_tag(value), separators=(',', ':'))
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/sessions.py", line 72, in _tag
return dict((k, _tag(v)) for k, v in iteritems(value))
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/sessions.py", line 72, in <genexpr>
return dict((k, _tag(v)) for k, v in iteritems(value))
File "/srv/www/li/venv/lib/python2.7/site-packages/flask/sessions.py", line 80, in _tag
u'base64 encoding your string (String was %r)' % value)
UnexpectedUnicodeError: A byte string with non-ASCII data was passed to the session system which can only store unicode strings. Consider base64 encoding your string (String was 'iB\rOU#\xf7BO\x08^\xa6\xd1)v\xad')
flask/app.py 第 1693 行的 self.save_session(ctx.session, response) 给出的是：flask.sessions.SecureCookieSession({'_id': 'iB\rOU#\xf7BO\x08^\xa6\xd1) v\xad', '_flashes': [('message', '请登录以访问此页面。')]})
所以，如果我没看错，会话会给出一个 id，flask 会尝试对其进行 unicode（并失败）。我不知道如何纠正这个问题（清空我的浏览器缓存以希望新的会话也无济于事）。谁能给我任何关于我应该做什么的建议？
亲切的问候，
卡斯特
编辑：一些额外的信息。我的设置使用了flask、flask_mail、flask.ext.mongoengine 和flask.ext.security；我使用 MongoEngine: db = flask.ext.mongoengine.MongoEngine(app) 和 flask-security: user_datastore = flask.ext.security.MongoEngineUserDatastore(db, User, Role) security = flask.ext.security.Security(app, user_datastore )
编辑：这似乎是一个双重问题： 烧瓶登录：TypeError：不支持解码Unicode
（没看过，抱歉）