error submitting grade to a skill in a cando project

[Susanne]

Hi.
I resently had to reinstall schooltool on our server. I chose to import the old dattabase, but now i get an errormessage when I make a new project in cando, then add skills in that project, and try to grade that skill. I can however grade skills in the skillset view in can do. How can i fix this? This happend a few times when I had the old versoin, but I fixed it by exporting the school, then clear the database, and import the xml file again. I cant do that now, because then we loose all the informasjon we have registerd on the students.

Here is the errormessage.

 Tjenerfeil

En intern tjenerfeil har oppstått. Dette betyr sannsynligvis at du har funnet et feil i SchoolTool. Vennligst rapporter dette på feilhåndtereren.

Unntak
AttributeError: 'NoneType' object has no attribute '__parent__'

Sporingsdata

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 205, 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.ProjectsGradebookOverview_index.html object at 0x7f675d8fc490>
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 98, in __call__
  self.update()
File "/usr/lib/python2.7/dist-packages/schooltool/gradebook/browser/gradebook.py", line 1167, in update
  GradebookOverview.update(self)
File "/usr/lib/python2.7/dist-packages/schooltool/gradebook/browser/gradebook.py", line 656, in update
  student['object'], activity, cell_score_value, evaluator)
File "/usr/lib/python2.7/dist-packages/schooltool/cando/gradebook.py", line 102, in evaluate
  equivalent = self.filterEquivalent(activity.findAllEquivalent())
File "/usr/lib/python2.7/dist-packages/schooltool/cando/gradebook.py", line 97, in filterEquivalent
  equivalent)
File "/usr/lib/python2.7/dist-packages/schooltool/cando/gradebook.py", line 96, in <lambda>
  lambda e: ISection(e.__parent__, None) is self.section,
File "/usr/lib/python2.7/dist-packages/zope/component/hooks.py", line 119, in adapter_hook
  return siteinfo.adapter_hook(interface, object, name, default)
File "/usr/lib/python2.7/dist-packages/schooltool/cando/gradebook.py", line 266, in getCourseSkillSetSection
  return worksheet.__parent__.__parent__

Modules

schooltool 2.8.5 (/usr/lib/python2.7/dist-packages)

schooltool.cando 2.8.2 (/usr/lib/python2.7/dist-packages)

schooltool.gradebook 2.8.4.1 (/usr/lib/python2.7/dist-packages)

schooltool.intervention 2.7.0 (/usr/lib/python2.7/dist-packages)

schooltool.lyceum.journal 2.8.2.1 (/usr/lib/python2.7/dist-packages)
Runtime

Python 2.7.6 (default, Jun 22 2015, 17:58:13) [GCC 4.8.2]

Linux schooltool 3.13.0-83-generic #127-Ubuntu SMP Fri Mar 11 00:25:37 UTC 2016 x86_64 x86_64

Filesystem encoding ANSI_X3.4-1968, preferred ANSI_X3.4-1968

[Susanne (seb1987)]

I really need help with this... what can i do to fix it?