AbsMaterial now includes thumbnailType method, subclasses will need to remove extend keyword if they had previously defined this method.
AbsMaterial public class AbsMaterial extends CachedMaterial { extend public gmThumbnailType thumbnailType() {..} } public class FOMaterial extends OfficeMaterial { Old: extend public gmThumbnailType thumbnailType() {..} New: public gmThumbnailType thumbnailType() {..} }