oh joy! it's a MethodInvocationException!

Message: Invocation of method 'getVehicleId' in class gr.netmechanics.platform.rentacar.site.BookingHelper$Proxy$_$$_WeldClientProxy threw exception java.lang.NullPointerException at WEB-INF/vm/_partials/booking_aside.vm[line 4, column 48]

Reference name: BOOKING_HELPER

Method name: getVehicleId