Snipper rejects features because of INVALID_GEOMETRY_TYPE

Try using a GeometryRefiner before the Snipper and see if that helps.

@david_r: Adding the GeometryRefiner makes no difference.

Can you save a single such feature in an FFS file and post it here for testing? You can either use the FFS writer or the Recorder transformer for this.

Hi @willyb, if the entire shape of the MultiCurve geometry is a single polyline, you can decompose the MutiCurve into individual Line parts with the Deaggregator and then combine the parts into a single Line geometry with the LineJoiner.

Note: The LineJoiner has been renamed to LineCombiner in FME 2017.

try geometryextractor and then replacer.