>>23701256Also, if you select a mesh and place a keyforms on a parameter, you gotta make sure you have keyforms on both extremes of the parameter. If you don't do this, they mesh will disappear when you're outside of the single keyform.
Maybe you're getting that error because the mesh you're using as the mask is missing a keyform. To ensure you don't get these types of errors, always start by using the buttons at the top, they automatically put keyframes on both extremes of the parameter.
