I'm processing the same data using almost equal parameters. The only difference are the *.args files. Below is the first one (peninsula.args), that compiles without errors: product-id=314 family-id=14 family-name=OSM España country-name=ESPAÑA country-abbr=ESP mapname: 63240001 description: ES-Madrid input-file: 63240001.osm.gz mapname: 63240002 description: ES-Vigo input-file: 63240002.osm.gz mapname: 63240003 description: ES-Valladolid input-file: 63240003.osm.gz mapname: 63240004 description: ES-Valencia input-file: 63240004.osm.gz mapname: 63240005 description: ES-Barcelona input-file: 63240005.osm.gz product-id=314 family-id=15 family-name=OSM Portugal country-name=PORTUGAL country-abbr=POR mapname: 63240006 description: PT-Lisboa input-file: portugal.osm The second one (spain.args) gives the following error: Too many blocks. Use a larger block size with an option such as --block-size=2048 or --block-size=4096). This is the content: product-id=314 family-id=14 family-name=OSM España country-name=ESPAÑA country-abbr=ESP mapname: 63240001 description: ES-Madrid input-file: 63240001.osm.gz mapname: 63240002 description: ES-Vigo input-file: 63240002.osm.gz mapname: 63240003 description: ES-Valladolid input-file: 63240003.osm.gz mapname: 63240004 description: ES-Valencia input-file: 63240004.osm.gz mapname: 63240005 description: ES-Barcelona input-file: 63240005.osm.gz As you see, it is the same than the first one without the last part of it, so what is processed with the second args file is also processed with the first one without problems. Has anyone an explanation for this? As use of --block-size is not recommended in options file, I would like to know if you have any other suggestion on how to proceed. My parameters are: time java -Xmx600m -enableassertions -jar mkgmap.jar --route --latin1 --code-page=1252 --gmapsupp --series-name="OSM-Iberia-n" --index --road-name-pois --ignore-maxspeeds --remove-short-arcs --add-pois-to-areas --adjust-turn-headings --report-similar-arcs --link-pois-to-ways --location-autofill=1 --drive-on-right --check-roundabouts --check-roundabout-flares --style=mio --delete-tags-file=quitar_is_in -c peninsula.args/spain.args Regards, Carlos