In Revit 2025 and 2026, the “Content Catalog – Launch as App” and “Launch in Browser” options are effectively useless unless you have an active US hub with the Content Catalog enabled.

Other regions, for example, the EU, are not supported by this add‑in, which makes these buttons non-functional. The only reliable way to access the Content Catalog is to open it manually in your preferred web browser.
Please avoid assuming that the US region is the only region that matters.