Steps to reproduce:

1. Configure two languages, for instance eng-GB and nor-NO.
2. Create the article in root location using English, let's name it ENG.
3. Create the second article in root location using Norwegian, let's name it NOR.
4. Go to edit mode of article ENG, save draft and close form using the left upper corner button X.
5. Again, go to edit mode of article ENG, create the new draft, save it and close the form using the left upper corner button X. You should have two different drafts saved.
6. Go to edit mode of article NOR, save draft and close form using the left upper corner button X.
7. Again, go to edit mode of article NOR, create the new draft, save it and close the form using the left upper corner button X. You should have two different drafts saved.
8. Go to Dashboard.
9. Find ENG article on the list and edit it using the pencil icon. Choose the newest draft (should be no. 3).
10. Do not change anything. Just click browser's back button when edit form loaded.
11. Find NOR article on the list and edit it using the pencil icon. Choose to create a new draft using + button in the modal window.

Result:
You will see 404 page. See the attached screenshot.

URL: /admin/content/edit/draft/98/4//96

Expected result:
A user should be redirected to the edit form.

Note:
In the URL which user is redirected to the language code is missing.

Note 1:
The customer reported this problem against v2.1.1, but there is no way to choose if in affected versions.