2011 Jaguar XF my xf 2011 - warning : water in fuel /washer fluid low with intermittent restricted power wasrning - and reduced power experienced.

Jaguar XF 2011 - shows warning : water in fuel and now changed to low washer fluid. This is with intermittent flashing of Restricted Performance. The power is restricted when this occurs.Have had the fuel filter changed but made no difference and washer fluid is full. Any sugestions?only second problem I've had since new, otherwise runs perfectly.