When trying to download a map, you might get an error message. Most often this is because the PNG-files (i e pictures) in your map is "interlaced". While interlaced images will work fine on screen, they will cause problems if you at any time want to download the map. Here is what to do:
When saving a picture as a PNG-file, make sure to save it as non-interlaced. Open the file in any image-editor. Look for a checkbox or a prompt when saving the file. You should check all your PNG-files to make sure that they are not interlaced before uploading to a journey map.