Whenever the settings and information on the FRITZ!Box are accessed via a browser, a session ID in the background is used to ensure that the access is authorized.

This status message appears after any attempt to access the FRITZ!Box user interface using an illegal session ID. Since all connections between the FRITZ!Box and your browser were ended to ensure security, you must log back on to the FRITZ!Box interface using your password.

Causes for an Invalid Session ID

• Note:While the FRITZ!Box user interface was open in your browser, another web page opened in your browser attempted to configure settings in your FRITZ!Box.
• You use supplementary software for the FRITZ!Box, for instance the "FRITZ!Box Monitor", which is can no longer be used in current operating systems or with the latest FRITZ!Box firmware.

Avoiding an Invalid Session ID

• We recommend that you do not surf in the Internet while you are logged on to the FRITZ!Box user interface. Leave the FRITZ!Box user interface by closing your browser and wait a moment before reopening the browser to surf.
• Note:Download the current versions of this free supplementary software for your FRITZ!Box by opening the "Programs" link at the lower right of the FRITZ!Box interface, selecting the desired program, and starting the download process.