Acer Aspire S5-391 - Manual (Page 77)

MagicFlip port door - 77
MagicFlip port door notification
When the door opens or closes, a notification will appear at the bottom of
the screen.
To hide the notification, click the icon.
If you press the MagicFlip port door button while there is a device plugged
into one (or more) of the ports, the notification will flash red borders
around the port icon(s) for the occupied port(s).
In the event that the application can’t identify what is causing the door to
be unable to close, all the port icons will be highlighted in red.