Vehicle Configuration Locked

I have been trying to change the fuel level in the vehicle configurator but when I make any changes the configuration menu becomes locked and will not work or close. It used to only happen when modifying the D-series but as of recent, it now does it with everything. Is there any way to stop it doing this?

 

How about if you pause physics and then try to adjust slider, then hit apply and unpause physics, does that work?

 

If I pause it I can move the sliders but then it freezes after I click the apply button, it has also been randomly crashing for some reason.