Xcode 7 warning: The launch image does not have a valid extension

Try changing Default@2x.png instead of Default@2x.PNG.

Can't comment, yet found this helpful:

After renaming the image's extension name to lowercase the warning goes away(as explained in the accepted answer: .PNG -> .png)

If the warning doesn't go away, clean the project by going to Product -> Clean

(or just: Shift + CMD + K)

ios xcode7 launchimage

If you have the file Image.PNG, convert it into Image.png, and if you have the file extension Image.JPG, convert it into Image.jpg.

Make sure your images have extension with lowercase letters, not capital letters. Hope this will help!

CodeHunter