If you can see catalogs but not a particular one it may be that the manufacturers catalog require you to have authorization to use their catalog.
Some catalogs require the manufacturer to authorize individual users to have access to the catalog. These catalogs appear with a lock on them in the content browser. To request access to a catalog that requires authorization, click on the lock to let the manufacturer now that you want access to your catalog. Once the manufacturer approves, you will see the lock change to a <+></+> or <-></-> sign and allow you to add it to your cloud browser.