Hi Ticker, I've now found the time to look at the details. The problem was not the size of the sub division but the number of Polyline instances created for the long road. This has to be < 0x80. The corresponding check was only implemented with an assert statement and Valentins call doesn't enable assertions, so invalid data was written. I've attached a patch which implements the splitting in StyledConverter and which throws a MapFailedException instead of using an assertion. Open problem: MapSplitter still SCHW: uk.me.parabola.mkgmap.build.MapSplitter f:\dwnload\temp\63240201.osm.pbf: Single item predicted to exceed subdivision http://www.openstreetmap.org/?mlat=10.489948&mlon=-13.065190&zoom=17 SCHW: uk.me.parabola.mkgmap.build.MapSplitter f:\dwnload\temp\63240201.osm.pbf: Single item predicted to exceed subdivision http://www.openstreetmap.org/?mlat=10.368004&mlon=-12.969704&zoom=17 while the map seems to be OK. So I think the estimation also needs a fix? Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von valentin3151@gmail.com <valentin3151@gmail.com> Gesendet: Dienstag, 4. August 2020 12:28 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] Error in Africa? Hi, Ticker. Thanks for your investigation. I am very impressed with how some people are using the wrong tags. With --x-no-mergeroads option, my problem was fixed. Great! Best regadrs, Valrntin _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev