Answer:
You should remove the user from each group that has denotative contradiction to access the file.
Step-by-step explanation:
This happens when the user is also a member of one or more such groups that do not allow users to access specific files. The controller get confused by having two options (have access , does not have access) and does not gives access to user for such files unless they are removed from the groups that have a contradiction for accessing that files.
I hope it will help you!