Artificial Intelligence proposes this.
The purple square featuring a vertical line and a star symbol signifies a sensor or electronic control unit alarm in your Mercedes W205.
This is a generic alert, frequently associated with a malfunction in a particular system, and it is generally accompanied by a supplementary message on the dashboard display that delineates the precise issue.
Proposed Measures
Verify for a supplementary message: The primary dashboard interface will probably exhibit language (e.g., "Inoperative", "Refer to Owner's Manual") elucidating the particular system experiencing the malfunction (e.g., Active Brake Assist, ESP, or a designated sensor).
Reinitialise the vehicle: The problem may occasionally stem from a transient electronic malfunction, which can be rectified by powering down the vehicle, removing the key for around 30 seconds, and then restarting the engine.
Exercise caution while driving: This symbol, when displayed in yellow or purple, indicates a caution rather than an immediate red-level safety concern, allowing you to proceed to a safe place or an authorised repair facility.
Seek the assistance of a technician: Due to the symbol's lack of specificity, a diagnostic scan instrument (OBD-II scanner) is required to ascertain the exact error code and underlying problem.