This problem was immediatley noticable after the last update, so I think it really has something to do with a graphical change from the Creative Assembly's side. If the HDR-Bloom graphic feature is active, a blinding white light appears (as if an atomic bomb has gone off) everytime that the canon balls hit the ground. Here is a video which I've made:
As you can see, as soon as I have deactivated the HRD-Bloom feature, there is no more problem. Here is exactly the same battle and the same canon shots, simply without HDR-Bloom:
Does anyone know what could cause this problem? Is there a patch for it or any other way of fixing this problem? Is there a way to report this bug to the Creative Assembly directly?