Where can I find WorldServer Project File Attributes on the server where WorldServer is installed?

The file attributes are stored in the Attributes folder on the server where WorldServer is installed.

The location of the Attributes folder depend on your WorldServer server configuration.

If you are not sure on the location you can check this in the general.properties file on your server by searching for this property: 

file_attribute_storage=

The value of this property will point to the folder path on your server, e.g.: #file_attribute_storage=c:/Shared/Attributes

Relevant articles:

After an SDL WorldServer upgrade, reference files/project attributes are no longer visible in active projects created before the upgrade
SDL WorldServer - Are project attributes and task attributes deleted from the 'Attributes' folder on the server once a project has been archived?
After upgrading WorldServer or after migrating it to a new server, file attributes of projects created before the upgrade or change cannot be downloaded anymore