When all check boxes are checked

I am using the following code in my contact form 7:

[checkbox checkbox-ac "A/C Service, "]

[checkbox checkbox-alignment "Alignment, "]

[checkbox checkbox-batteries "Batteries, "]

[checkbox checkbox-BGservices "BG Services, "]

[checkbox checkbox-brakes "Brakes, "]

[checkbox checkbox-coolingsystem "Cooling Systems, "]

[checkbox checkbox-electricalSystem "Electrical System & Component Repair, "]

[checkbox checkbox-engineperformancediagnosis "Engine Performance Diagnosis, "]

[checkbox checkbox-engineRepair "Engine Repair, "]

[checkbox checkbox-exhaustRepair "Exhaust Repair, "]

[checkbox checkbox-LiftKists "Lift Kits, "]

[checkbox checkbox-offRoad "Off Road, "]

[checkbox checkbox-offRoadAccessories "Off Road Accessories, "]

[checkbox checkbox-oilChange "Oil Change, "]

[checkbox checkbox-performanceModifications "Performance Modifications, "]

[checkbox checkbox-steeringSuspension "Steering and Suspension, "]

[checkbox checkbox-suspensionLifts "Suspension Lifts, "]

[checkbox checkbox-vehicleInspection "Texas State Vehicle Inspection, "]

[checkbox checkbox-tires "Tires, "]

[checkbox checkbox-transmissionServiceRepair "Transmission Service & Repair, "]

[checkbox checkbox-vehicleMaintenance "Vehicle Maintenance, "]

[checkbox checkbox-factoryScheduledMaintenance "Factory Scheduled Maintenance, "]

[checkbox checkbox-prepurchasedVehicleInspections "Pre-Purchased Vehicle Inspections, "]

[checkbox checkbox-serviceWarranty "Service Warranty, "]

How do I configure the “Conditional Fields” so that when all check boxes are checked, it should throw an error message?

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