Ah, I see.
The ⚠️ means that the car's performance can no longer be simulated, so it's not possible to determine a Performance Point value.
Generally this could be down to overly sticky tyres or weird suspension settings (particularly too low or stiff), but I recall it could also happen previously with mad gearbox settings - basically making the car undrivable for the simulation.
Engine swaps, particularly very powerful ones on old cars, can generate it too as they can suddenly overwhelm the tyres or suspension, so replacing tyres with less grippy items or reverting suspension to Sports should fix it.