Start by comparing Finder and the Dock. If Finder shows the new icon but the Dock does not, reopen the app and check the Dock shortcut. If both show the old icon, check the selected app, the result of the icon change, and any permission message. After an app update, you may need to apply your custom icon again.
Updated October 12, 2026. NyaIcon instructions apply to its macOS Tahoe 26 workflow. Menu labels and compatibility can differ on other releases.
1. Identify which result you are seeing
- The new icon appears in Finder only: continue with the Dock checks below.
- Neither Finder nor the Dock changes: confirm you changed the installed app, rather than an alias, an installer, or another copy.
- A generic image-file icon appears: copy the image inside Preview instead of copying the image file in Finder.
- It worked until an update: finish the update, then reapply the icon to the current installed app.
- NyaIcon reports a failure or asks for approval: follow that message before repeating the change.
2. If only the Dock shows the old icon
- Save your work, quit the affected app, and reopen it from Applications in Finder.
- Check whether you have multiple copies of the app. Use the copy you actually want to launch.
- If the pinned Dock shortcut still looks wrong, remove it from the Dock and add the intended app again. Remove the shortcut only; keep the app in Applications.
- If the mismatch remains, save your work and restart the Mac, then compare Finder and the Dock again.
These steps help distinguish a stale display or shortcut from an icon change that never completed. They are troubleshooting checks, not a guarantee that every icon cache issue will disappear. You do not need to delete broad system caches to perform them.
3. If a Finder paste does not work
Open the artwork in Preview and copy the image. In Finder, select the intended item, open File → Get Info, select the small icon at the top, then paste. The large preview lower in the window is not the paste target. This image-copy workflow is documented in Apple’s file and folder icon guide.
If Paste remains unavailable, try an ordinary folder you created and can edit. A successful folder test helps separate an image-copy problem from a restriction on the original target. Protected Apple applications have different constraints; see system app compatibility.
4. If an icon reverted after an app update
An updater can replace the installed app or its icon resources, so a previously applied custom icon may no longer appear. Keep the source artwork or the name of your theme so you can apply it again after the update completes. Check that the app still opens normally before customizing it.
In NyaIcon, find the current installed app and apply its icon again. For a matching app theme, open the theme and use Reapply if that action is available. Read the result before retrying. A theme applies to matching supported apps; it does not automatically customize every installed app or folder.
A macOS upgrade is a separate compatibility change. NyaIcon’s stated platform is macOS Tahoe 26. Check support for your exact release before applying icons, and report failures instead of assuming an older successful change will work on a newer system.
5. If NyaIcon reports an approval or restore problem
NyaIcon uses its IconServices Helper for app icon changes and may request macOS approval. Follow the recovery action shown by NyaIcon, including a restart when requested. A pending approval is not fixed by repeatedly applying the same theme. Keep the exact error message if the operation still fails.
If you want to return to the previous look, use NyaIcon’s restore actions. Remove Theme removes the active theme’s app changes while keeping individually applied icons. Restore All is broader. Read the restore guide before choosing it.
What to include in a support request
- Your exact macOS and NyaIcon versions.
- The affected app name, version, and its Finder location.
- Whether you used Finder, an imported icon, or a NyaIcon theme.
- Whether Finder, the Dock, or both show the wrong icon.
- The exact error and whether the issue started after an app or macOS update.
Send those details through Help & Support. A screenshot can show the mismatch; crop out private documents and notifications.
Once the issue is resolved, use the app icon guide for the full customization workflow or browse matching themes.