Xcode10 Validating: No transparencies in my images but still not accepting?

Question

Everything was OK on previews versions and I am 100% sure that all my images and icons (icon-1024.png included) has no "transparencies" plus has no "alpha channels" also,

Then, I am trying to validate my APK by the menu "Organizer" BUT, getting the same error message:

Invalid App Store Icon.
The App Store Icon in the asset catalog in 'nonono.app' cant be transparent nor contain an alpha channel.

The tools I used to adjust my images:

https://appiconmaker.co,
https://makeappicon.com     
and 
mogrify -alpha off res/icon/ios/*.png

and here a print from my mac:

and another from xcode:

What I am doing wrong? I appreciate any tips! everything was OK on previews versions!!

Thanks.

Answer 1

I've met this case before, you can try steps below to remove the alpha channel:

1. Open your example.png image with the Preview.app.

2. Press CmdShifts to "save as" the image, you'll get a new copy.

3. Press Cmds to save the new copy, in this step, you'll get a setting dialog like screenshot below, just uncheck that "Alpha" checkbox, and save the new copy as your example.png file.

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Note: Make sure your uploaded images have no alpha channel in two places below ("App Previews and Screenshots", and "App Store Icon" in General App Information section):

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If you checked and all are fine. One more suggestion: "save as" your image twice (open the image w/ Preview.app, then press CmdShifts twice, you'll get a "* copy 2.png" file). Remove that copy's alpha channel and save it.

Cause I just tried this in one of your image, notice the image has a smaller size, which might lead by removing the real alpha channel.