No, it wouldn’t – the presence or absence of the license key should have no affect on this whatsoever.
The first thing to do here is check that all of your Modern Tribe plugins are up to date (if you are having difficulties with your license key consider uploading new copies manually – you can grab our premium plugin downloads over here) – and also ensure you are running at least WordPress 3.5. If that doesn’t help please deactivate all non-Modern Tribe plugins and switch to a default, unmodified theme and see if that resolves this.
Thanks!