Is the problem a file read error or an error in creating an image object from the file data? Could it be a "file-in-use" problem where your app isn't closing the file?
Thanks for getting back.
These were my initial thoughts, but as the file can be opened with Photoshop then the file must be created correctly and fully?
Any other ideas gratefully recieved!
Well, some programs happily open files that are currently open by another process, others don't. It shouldn't be too hard to test, though, by creating the file, closing the AIR app and then opening the file with a program that couldn't before.
It could be an encoding issue, but it would be strange that the JPEGDecoder couldn't open a JPEG created by JPEGEncoder.
Finally, it could be a bad file write somehow, with Photoshop having a more robust decoder that can recover from some file errors that the others can't.