After upgrading from r1441 to r1572 using --map-features broke for me: $ java -Xmx1024M -enableassertions -jar /home/avar/src/osm.nix.is/mkgmap/dist/mkgmap.jar --map-features=cycling-map-features.csv Iceland-cycle.osm java.lang.NullPointerException at java.util.ArrayList.addAll(ArrayList.java:472) at uk.me.parabola.mkgmap.osmstyle.RuleIndex.addChangables(RuleIndex.java:249) at uk.me.parabola.mkgmap.osmstyle.RuleIndex.addRuleToIndex(RuleIndex.java:103) at uk.me.parabola.mkgmap.osmstyle.RuleSet.add(RuleSet.java:97) at uk.me.parabola.mkgmap.osmstyle.StyleImpl.addBackwardCompatibleRules(StyleImpl.java:317) at uk.me.parabola.mkgmap.osmstyle.StyleImpl.initFromMapFeatures(StyleImpl.java:288) at uk.me.parabola.mkgmap.osmstyle.StyleImpl.readMapFeatures(StyleImpl.java:270) at uk.me.parabola.mkgmap.osmstyle.StyleImpl.<init>(StyleImpl.java:141) at uk.me.parabola.mkgmap.reader.osm.xml.Osm5MapDataSource.createStyler(Osm5MapDataSource.java:120) at uk.me.parabola.mkgmap.reader.osm.xml.Osm5MapDataSource.load(Osm5MapDataSource.java:80) at uk.me.parabola.mkgmap.main.MapMaker.loadFromFile(MapMaker.java:148) at uk.me.parabola.mkgmap.main.MapMaker.makeMap(MapMaker.java:56) at uk.me.parabola.mkgmap.main.Main$1.call(Main.java:189) at uk.me.parabola.mkgmap.main.Main$1.call(Main.java:186) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:619) Exiting - if you want to carry on regardless, use the --keep-going option The files needed to reproduce it are here: http://v.nix.is/~avar/mkgmap/npe/