When using Google Adwords Editor to upload images for display ads and the images have spaces in the file name (e.g., leaderboard 200×600 catfood.jpg), the space can only be a single space.
If there is a double space between words, AE will report the image is blank and refuse to upload it.
Solution: Edit the file names to remove double spaces.
Better Solution: Google Adwords Editor should show a warning that explains the problem so the user can fix it (for example, “Please remove double spaces in the file name.”), instead of just saying “blank image”. The image isn’t blank so the message is misleading and useless.