Hi Ize
Apparently I made a mistake in the demo and set an event to create the metaball objects in the layer with index 2, while there's only two layers and the maximum index is 1. Probably something I missed when cleaning the example for release.
Fortunately C2 corrects my mistake by automatically getting the next valid index instead of crashing, which is 1. When you create a new layer, index 2 starts to be valid and the objects are created in a layer that doesn't have the effect.
So, there's no problem with the effect, it's working as intended. It's just my example that's faulty. I will correct it and reupload later.