I've tried all of these solutions (How to clip a line layer based on polygons with QGIS?) and still can't clip a shapefile. I'm trying to create a coastal shapefile for one region (NW France) from a world coastline. I created a custom rectangle to use as the clip extent and used vector> geoprocessing> clip to attempt the clip. Still no progress. Has anyone had success using other techniques or can anyone see a problem with my method?
I'm using QGIS 2.12.