Exception
AttributeError: 'NoneType' object has no attribute '__name__'

Traceback
File "/usr/lib/python2.7/dist-packages/zope/publisher/publish.py", line 132, in publish
  result = publication.callObject(request, obj)
File "/usr/lib/python2.7/dist-packages/zope/app/publication/zopepublication.py", line 207, in callObject
  return mapply(ob, request.getPositionalArguments(), request)
File "/usr/lib/python2.7/dist-packages/zope/publisher/publish.py", line 107, in mapply
  return debug_call(obj, args)
Extra information: <schooltool.skin.flourish.zcml_content.ManageSchool_manage object at 0xac5152c>
File "/usr/lib/python2.7/dist-packages/zope/publisher/publish.py", line 113, in debug_call
  return obj(*args)
File "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/page.py", line 93, in __call__
  result = self.render(*args, **kw)
File "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/page.py", line 54, in render
  return self.template(*args, **kw)
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 83, in __call__
  return self.im_func(im_self, *args, **kw)
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 51, in __call__
  sourceAnnotations=getattr(debug_flags, 'sourceAnnotations', 0),
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 132, in pt_render
  strictinsert=0, sourceAnnotations=sourceAnnotations
Template "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/templates/main.pt"
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 240, in __call__
  interpreter()
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 271, in __call__
  self.interpret(self.program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 343, in interpret
  handlers[opcode](self, args)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 533, in do_optTag_tal
  self.do_optTag(stuff)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 518, in do_optTag
  return self.no_tag(start, program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 513, in no_tag
  self.interpret(program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 343, in interpret
  handlers[opcode](self, args)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 742, in do_insertStructure_tal
  structure = self.engine.evaluateStructure(expr)
File "/usr/lib/python2.7/dist-packages/zope/tales/tales.py", line 696, in evaluate
  return expression(self)
Template "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/templates/main.pt", line 79, column 8
  Expression: <PathExpr standard:u'view/page_template|nothing'>
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 217, in __call__
  return self._eval(econtext)
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 211, in _eval
  return ob()
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 83, in __call__
  return self.im_func(im_self, *args, **kw)
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 51, in __call__
  sourceAnnotations=getattr(debug_flags, 'sourceAnnotations', 0),
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 132, in pt_render
  strictinsert=0, sourceAnnotations=sourceAnnotations
Template "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/templates/page.pt"
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 240, in __call__
  interpreter()
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 271, in __call__
  self.interpret(self.program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 343, in interpret
  handlers[opcode](self, args)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 583, in do_setLocal_tal
  self.engine.setLocal(name, self.engine.evaluateValue(expr))
File "/usr/lib/python2.7/dist-packages/zope/tales/tales.py", line 696, in evaluate
  return expression(self)
Template "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/templates/page.pt", line 23, column 2
  Expression: <PathExpr standard:u'view/providers/page_content|nothing'>
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 217, in __call__
  return self._eval(econtext)
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 211, in _eval
  return ob()
File "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/content.py", line 56, in __call__
  return self.render(*args, **kw)
File "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/page.py", line 152, in render
  result = ViewletManager.render(self, *args, **kw)
File "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/viewlet.py", line 236, in <lambda>
  render = lambda self, *args, **kw: self.template(*args, **kw)
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 83, in __call__
  return self.im_func(im_self, *args, **kw)
File "/usr/lib/python2.7/dist-packages/schooltool/common/inlinept.py", line 110, in __call__
  showtal=getattr(instance.request.debug, 'showTAL', False),
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 132, in pt_render
  strictinsert=0, sourceAnnotations=sourceAnnotations
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 240, in __call__
  interpreter()
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 271, in __call__
  self.interpret(self.program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 343, in interpret
  handlers[opcode](self, args)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 821, in do_loop_tal
  self.interpret(block)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 343, in interpret
  handlers[opcode](self, args)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 533, in do_optTag_tal
  self.do_optTag(stuff)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 518, in do_optTag
  return self.no_tag(start, program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 513, in no_tag
  self.interpret(program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 343, in interpret
  handlers[opcode](self, args)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 583, in do_setLocal_tal
  self.engine.setLocal(name, self.engine.evaluateValue(expr))
File "/usr/lib/python2.7/dist-packages/zope/tales/tales.py", line 696, in evaluate
  return expression(self)
Template "None", line 3, column 10
  Expression: <PathExpr standard:'viewlet'>
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 217, in __call__
  return self._eval(econtext)
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 211, in _eval
  return ob()
File "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/viewlet.py", line 74, in __call__
  return self.render(*args, **kw)
File "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/page.py", line 183, in <lambda>
  render = lambda self, *a, **kw: self.template(*a, **kw)
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 83, in __call__
  return self.im_func(im_self, *args, **kw)
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 51, in __call__
  sourceAnnotations=getattr(debug_flags, 'sourceAnnotations', 0),
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 132, in pt_render
  strictinsert=0, sourceAnnotations=sourceAnnotations
Template "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/templates/page_content.pt"
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 240, in __call__
  interpreter()
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 271, in __call__
  self.interpret(self.program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 343, in interpret
  handlers[opcode](self, args)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 583, in do_setLocal_tal
  self.engine.setLocal(name, self.engine.evaluateValue(expr))
File "/usr/lib/python2.7/dist-packages/zope/tales/tales.py", line 696, in evaluate
  return expression(self)
Template "/usr/lib/python2.7/dist-packages/schooltool/skin/flourish/templates/page_content.pt", line 1, column 0
  Expression: <PathExpr standard:u'view/body_template'>
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 217, in __call__
  return self._eval(econtext)
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 211, in _eval
  return ob()
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 83, in __call__
  return self.im_func(im_self, *args, **kw)
File "/usr/lib/python2.7/dist-packages/zope/browserpage/viewpagetemplatefile.py", line 51, in __call__
  sourceAnnotations=getattr(debug_flags, 'sourceAnnotations', 0),
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 132, in pt_render
  strictinsert=0, sourceAnnotations=sourceAnnotations
Template "/usr/lib/python2.7/dist-packages/schooltool/timetable/browser/templates/f_manage_timetables_overview.pt"
File "/usr/lib/python2.7/dist-packages/zope/pagetemplate/pagetemplate.py", line 240, in __call__
  interpreter()
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 271, in __call__
  self.interpret(self.program)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 343, in interpret
  handlers[opcode](self, args)
File "/usr/lib/python2.7/dist-packages/zope/tal/talinterpreter.py", line 583, in do_setLocal_tal
  self.engine.setLocal(name, self.engine.evaluateValue(expr))
File "/usr/lib/python2.7/dist-packages/zope/tales/tales.py", line 696, in evaluate
  return expression(self)
Template "/usr/lib/python2.7/dist-packages/schooltool/timetable/browser/templates/f_manage_timetables_overview.pt", line 1, column 0
  Expression: <PathExpr standard:u'view/timetables_url'>
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 217, in __call__
  return self._eval(econtext)
File "/usr/lib/python2.7/dist-packages/zope/tales/expressions.py", line 211, in _eval
  return ob()
File "/usr/lib/python2.7/dist-packages/schooltool/timetable/browser/app.py", line 286, in timetables_url
  self.schoolyear.__name__)