camera fault message on dash no cameras working including reversing camera. Any ideas 2011 model year l322 td4.4vg

Mine does that very occasionally. Normally resets itself next time out, so obvious question:

"Have you tried turning it off and on again?" 2012 (L322) 4.4TDV8 Vogue SE, RSE, Fuji White over Arabica.
Previous V8s: BMW 645Ci, P38 4.6, P38 4.0, Merc CL500
Previous others: Honda x1, Volvo x7, Rover x6, BMW x6, Ford x1, Mercedes x2, Skoda x3, VW x2, Renault x2, Citroen x1, Mazda x3, Nissan x1, Audi x3, Kia x1, Fiat x4, Subaru x3, Austin x2, Triumph x2, Jeep x2, Hyundai x2, Lexus x1, Mitsubishi x1, Saab x2... and some others I've forgotten!

Yes turned off locked car tried later same fault no cameras working. reversing camera and surround cameras are fused from different fuse boxes, so is there a common control unit for both?