The customer observed that adding new translation fails under some conditions.

Steps to reproduce:
1. Add two new languages e.g. Polish and French both in BO and under ezpublish.system.admin_group.languages key.
2. Create a new Article in the default language (English) and add a polish translation.
3. Create a new user "testUser".
4. Add him the following permissions:

5. Login as "testUser".
6. Go to "test" content object and switch to Translations tab.
7. Try to publish "French" translation.

Result:
You will be presented with similar error (see stacktrace.png for more details):

User does not have access to 'edit' 'content' with: contentId '132'

Note:
The issue is gone after adding Polish and English language as a limitation to Content\Edit policy.