Find out WHY a user does not have access

So, I think I have configured everything correctly. User has read/write access to the shared folders. But obviously something is wrong somewhere. Because some folders work, and others do not.

Is there a way to tell why a specific user can't access a specific folder? As once I know why, I can correct the issue.

Thank you. I should have posted when I got it fixed. Turned out one of the users logged in from the computer had deny permissions for the folders.

Would still be nice to see somewhere in a log or something that says "User <name> was denied permission to access <folder> because <other user> is denied access to <folder>