hai, I noticed that the tile ID under properties in the gui start at zero (“0”), while the actual data in the file starts with ID=1, where ID=0 means empty.
So, the ID in the gui should start at ID=1 as well, right?
No. The tile ID in the GUI is the ID of the tile within its Tileset, while the ones in the files are global tile IDs, which indeed use 0 for empty, but the actual IDs used for the tiles may be completely different from the tileset-local IDs, since a map may have multiple tilesets, and two different maps may assign different GIDs to the same tiles.