To use some of the functionality in Bridge GeoServer extensions are required. You can download the required extensions matching the version number of your GeoServer installation on the GeoServer web page.
To publish ArcSDE layers to Esri ArcSDE® datastores in GeoServer it is required to have GeoServer ArcSDE® datastores extension installed. Make sure to install the version of the extension that matches the version number of your GeoServer installation.
To publish chart symbology it is required to have GeoServer Chart extension installed when running GeoServer with a version older than 1.7.5. Make sure to install the version of the extension that matches the version number of your GeoServer installation. From 1.7.5 onwards there is no need to install an extension to have chart supports.
To use GeoPackage as transport format in Bridge, install the GeoPackage extension for GeoServer. Make sure to install the version of the extension that matches the version number of your GeoServer installation. A prerequisite for the GeoPackage extension is the Web Processing Service (WPS) extension, so make sure to first install the WPS extension before installing the GeoPackage extension.