When you say the attributes are missing? Do you mean missing or are they just unexposed?

they appear with the original name (no prefix) and the values are all 'missing'

So if you click on the feature and look at it in the FeatureInformation window, you should see your new attributes there with values. Because you are using a dynamic value within the BulkAttributeRenamer, you won't see them exposed on the canvas

Ok thanks. That's not a working solution for me then. I need to be able to see the field names in the workbench as I go along so I know what fields are from what tables. Looks like its a case of manually copy and pasting it for every table I bring in.

Personally I wish there was just a check box to add the table name to the field name without having to add a bulk attribute renamer in in the first place.

Which transformer are you using to perform the join? E.g. the FeatureMerger has an option to prefix supplier attribute names in case of conflicts.

Alternatively, you can prefix the attribute names before the join.