First make sure your Directory Service Connector is set up properly. For that, go to the QMC, System, Setup, Directory Service Connectors, expand your DSC@Servername, seelect Active Directory add a new one if you don't have any clicking on the green plus sign at the top right, click in the Get Default icon just before the User Name.
If you don't see a small red asterisk at the right of the Password textbox, then click Apply and check for users again. If you do see the red asterisk, then add a username and password with privileges to read from the AD (usually, any domain account will do).
Second, make sure this three users have some information related to their restrictions in section access. The best way to test this is to download a local copy in the computer of these users, then open QlikView Desktop and see whether or not the document opens.
Third, make sure that they are authorized to see the document:
- If using DMS, in the QMC, Documents, User Documents, expand and click on the document with issues and click on the Authorization tab.
- If using NTFS permissions, then make sure these users have permissions to read and modify on the folder that stores this file, or the file itself.
Hope that helps.