[Samba] GPO Security Filtering "Access Denied"

[Miguel medalha]

I once had a similar problem and it turned out as this:

A Microsoft security update for Group Policy changed the behavior of clients in regards to GPOs:

MS16-072: Security update for Group Policy: June 14, 2016
https://support.microsoft.com/en-gb/kb/3159398


The following page explains the issues and the corrective measures. 
https://support.microsoft.com/en-gb/kb/3163622

In sum:

    Add the Authenticated Users group with Read Permissions to the Group Policy Object (GPO).
    If you are using security filtering, add the Domain Computers group with read permission.