Enhanced Compressed Wavelet (.ecw) files
EclipseCrossword saves crossword puzzle files with the .ecw extension. (For example, “My crossword.ecw”.) Due to an unfortunate coincidence, this same file extension is also used by another completely different type of file, an Enhanced Compressed Wavelet image. These types of files are usually maps, satellite images, or other similar large photos. If you have been given an .ecw file and EclipseCrossword tells you that it’s not a crossword puzzle, it may be an Enhanced Compressed Wavelet file.
How to open Enhanced Compressed Wavelet files
EclipseCrossword’s good at crossword puzzles, not satellite images, so you’ll need a different program to open that file. IrfanView is a popular free program for Windows that has been around for decades and can be used to open those types of pictures.