Can you provide information about your server environment? What version of Tableau Server / Tableau Online are you using? There's a lot of questions that need to be answered before narrowing down the issue. Here's some things to think about.
- Are you using SSL? If so, have you attempted to type in the fully qualified domain using https://tableauserver.domain.com
- What is the tableau server address your user(s) using? Are users able to log in and view project folders from the drop down list in Tableau Desktop?
- Have you validated that you've set the permissions on the project folder and 'Assigend permission to contents'
- Have you validated the permissions within Tableau Server?
This happens while publishing to a particular project or all projects? I suspect the project you are publishing to has custom permissions that denies publishing. You can check by going to Site > Content > Projects
On the top right corner or your selected Project (in my example it's the default proj), click on the 3 dots on the top right corner > Permissions
Next you'll see Permissions for your selected project. Do you see anything weird?