When preparing to submit your iOS app to the App Store, you may encounter an error message such as "Error ITMS-90717: Invalid App Store Icon". This error typically arises during the app validation process in Xcode or Application Loader and can suspend your app submission. Let’s delve into the technical details of this error and how you can resolve it.

Understanding Error ITMS-90717

Error ITMS-90717 occurs when there is an issue with your app's app icon file. Apple has specific requirements for these icons, and any deviation from these can result in the submission being rejected. Below are the common causes and solutions for the invalid app store icon error.

Technical Details

1. Resolution and Size Requirements:
   • Your app icon must have precise dimensions. For example, the app icon must be 1024x1024 pixels for the App Store submission. Any deviation from this size can trigger Error ITMS-90717. Icons meant for other uses, e.g., iOS home screen, have their own dimension requirements which should not be confused with the App Store icon.
2. Format and Color Space:
   • The icon image must be in PNG format. If your icon is in JPEG or any other format, convert it to PNG before submission.
   • Ensure that the image uses the RGB color space and not CMYK, as the latter is typically used for print and is not compatible with app store submissions.
3. Alpha Transparency:
   • The app icon should not contain any transparency. Icons with alpha channels will be rejected. Verify that your icon does not have any transparent pixels.
4. Naming and Placement:
   • Double-check the app icon's naming convention. Ensure you are following Apple’s guidelines for naming and placing the icon within the app bundle. The icon file should be named appropriately and be located within the app's asset catalog.

Examples of Misconfigurations

• App icon submitted with dimensions of 1000x1000 pixels instead of 1024x1024 pixels.
• Icon image saved as TIFF instead of PNG.
• An alpha channel present when the transparency was mistakenly added during the design process.
• Icon file placed outside the specified asset catalog.

Resolving the Issue

Here are steps to troubleshoot and resolve Error ITMS-90717:

1. Verify Dimensions:
   • Open your icon in an image editor and confirm it is exactly 1024x1024 pixels.
2. Check File Format:
   • Use an image editing tool or a converter to ensure your icon is saved in PNG format. Many free online tools can help with this if needed.
3. Remove Transparency:
   • Validate there is no transparency by examining the icon in an editor capable of displaying layers and channels. Flatten the image and ensure all layers are combined without transparency.
4. Monitor the Asset Catalog:
   • Make sure the icon is correctly placed within the asset catalog of your Xcode project. Go to the 'Images.xcassets' directory, and confirm that the icon appears under "AppIcon" with the right name.

Key Points Summary

Additional Considerations

• Retina Display Support: Ensure you have included all necessary icon sizes for different devices and Retina displays as required in the asset catalog.
• Automatic Compression: When exporting your PNG, be wary of settings that might cause automatic alteration, like adding an alpha channel or changing the color profile.
• Xcode Configuration: Check that your Xcode’s build settings are referencing the correct asset catalog containing your app icon.

By adhering to these guidelines and carefully checking your app icons, you can resolve Error ITMS-90717 and proceed with your app submission smoothly. Remember, the presentation of your app icon is one of the first interactions users have with your app, and ensuring its correctness is crucial in leaving a positive impression.