Hi Thomas, so mkgmap found out that you have a bad sea.zip. I would say this is a good reason to download a new one (or restore an older if this is brand new). At least you should check if your map contains flooded areas. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Thomas Morgenstern <webmaster@img2ms.de> Gesendet: Mittwoch, 5. Mai 2021 18:08 An: Development list for mkgmap Betreff: [mkgmap-dev] mkgmap r4693 , Error Seagenerator: precomp sea data seems to be wrong... Hi, i tested mkgmap-r4693. It give many errors. r4680 gives not such errors. #Schwerwiegend (Seagenerator): <path to osm.pbf file' : Precompsea data seems to be wrong, land-only tile is flooded around -... see Screenshot [cid:part1.31A8984A.A1B8BF38@img2ms.de]