Resolution
Check the configuration for native_api.allowed_paths.
On the computer running Tableau Server, open a command prompt as an administrator and navigate to the Tableau Server bin folder, located by default at C:\Program Files\Tableau\Tableau Server\<version>\bin
.
Enter the following command:
tabadmin get native_api.allowed_paths
If the value returned is something other than default (which is "*") then Tableau Server will only allow file-based data sources from specific locations. Set it back to default, or add specific locations separated by a a semicolon (;) to allow new locations to be used.
To return the setting to default:
On the computer running Tableau Server, open a command prompt as an administrator and navigate to the Tableau Server bin folder, located by default at C:\Program Files\Tableau\Tableau Server\<version>\bin
.
Enter the following commands:
tabadmin stop
tabadmin set native_api.allowed_paths -d
tabadmin configure
tabadmin start