IE11 compatibility issue using tabs

Hello everybody,

I’ve discovered an incompatibility with IE11. Just have a look at the following webpage:
http://lambewn73.seventythree.axc.nl/diensten/

You can change tabs by clicking on it. Works fine on every browser except in IE11 and 10.
I did several tests and it works fine when for example twenty sixteen theme is activated. So something in the Vantage theme is blocking the functionality of the tabs.

Not sure what it is as I’m not a developer. Any idea’s?

Thanks,
Lamberbee