In the browser cache, the web browser temporarily stores websites and pictures. If websites are visited frequently, the data does not need to be downloaded from the Internet again. In this way, websites can be displayed faster. During the firmware update of the Homematic Central Control Unit, some data of the CCU2 that is stored temporarily in the browser cache will be updated. To avoid any problems during the update of a new firmware version we recommend to clear the browser cache after each update.