The folowing line works for me in 3.4.3 and 3.7 (built today) but not in 3.6.0 from processing.algs.qgis import PolygonsToLines Could anyone test in the python console and confirm? Thanks! Raymond -- Terglobo Fahrenheitstraat 1 5223 BJ 's-Hertogenbosch The Netherlands +31 (0) 6 25 31 49 83