Hi Mike, I agree that the message should be improved. In fact I am always unsure what kind of limit this is. I've just created a working single tile map of Berlin including NOD which has a filesize of > 21MB. Your patch reports a number which probably counts bytes (I miss that info), but I think it is not about tile/map size. I assume it is about max. sub file size. So, maybe show that sub file name also? Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Mike Baggaley <mike@tvage.co.uk> Gesendet: Mittwoch, 24. Februar 2021 00:16 An: 'Development list for mkgmap' Betreff: [mkgmap-dev] Overview Too Big Hi Gerd, The error message that mkgmap outputs when the overview map is too big is not helpful. Please find attached a patch that improves this. Cheers, Mike