Try to check permissions on the project/workbook on the server.
Couple of things to remember:
1. "None" isnt the same as "denied". You might want to "deny" access to all users.
2. If there is a user level rules existing, this will trump the group level rules. If you have used default settings from installation, then this is quite likely the case.
Thanks for your suggestions!
I checked the permissions on the project/workbook and those permissions are the same as the project. I didn't think project permissions overwrite data source permissions. The data source is published to "default" the dashboard is published to project "x".
I also flipped the "All Users" to Deny on the data source. This still didn't work.
This doesn't make any sense. I used to manage data sources that were only data extracts and not live connections. If I didn't add the person to the data source permissions then they could see the workbook in the project but they would get an error message that said something like "hey you don't have permissions to access this".
Is this because the data source I'm using is a live connection to a SQL database?
Hmm.. that doesnt make sense. As long as you are accessing a data source published in tableau server in your workbook (and not accessing the data source directly), it should not matter whether it is live or extract. I would suggest contacting support and seeking their help in case something else is going on.
I had the same issue (in a testing environment). After digging around I discovered that you need to set the Data Source permissions when publishing the workbook to "Prompt User" and not "Embedded Password". After that it works as expected.
Documentation is here: Permissions Reference
Dan is correct. This is expected behavior. If workbook publishers embedded data source password when published the workbook, basically the workbook publisher allows workbook interactor to 'see' the data via workbook. The workbook interactors will not be able to connect to the data sources via Desktop except the two users who have data source connect permission. Please read my blog about Tableau permissions @ SCALING TABLEAU (7/10) – UNDERSTAND SERVER PERMISSIONS - Silicon Valley Enterprise Tableau User Group
Pls register for July 14's Tableau Administrators Virtual User Group | Tableau Software where I will present Understanding Tableau Server Permissions.