Check shapefile validity

qgis/export.py

@@ -61,6 +61,13 @@ def unique_attributes(layer):
 map_layers = project.mapLayers().items()
 layers = [v for k, v in map_layers if re.search(r'\d{4}', v.name())]
 
+try:
+    next(layers[0].getFeatures())
+except StopIteration:
+    msg = 'No hazard lines found. Check shapefile data.'
+    raise ValueError(msg)
+
+
 # Get all EP values and profile types from first hazard line layer
 eps, types, years = unique_attributes(layers[0])