When uploading an IPA to the App Store and encountering “Invalid Signature” or “Application failed codesign verification” errors, the issue is usually related to the signing process, not necessarily the certificate itself. Troubleshooting from a few directions can generally identify the cause.

Incorrect Certificate Type

The most common cause of Invalid Signature is packaging with a development certificate. An IPA signed with a development certificate can only be installed on test devices with UDID added, and cannot be submitted for release. Uploading to the App Store requires an IPA signed with a distribution certificate (iOS Distribution).

Check method: In Appuploader’s certificate management, view the certificate type. The Development type is a development certificate, while the Distribution type is a distribution certificate. If there is no distribution certificate in the list, create one first. When creating, select iOS Distribution, fill in the name and password, and the tool automatically generates it from the Apple server.

When packaging, you also need to select the corresponding distribution provisioning profile (App Store type), ensuring the certificate referenced by the profile is the distribution certificate.

Certificate and Provisioning Profile Mismatch

A provisioning profile is bound to a specific certificate. If the profile references certificate A, but the actual certificate used during packaging is certificate B, signature verification will fail.

Troubleshooting: Check the contents of the provisioning profile, which includes certificate information and Bundle ID. In Appuploader’s provisioning profile management, you can view detailed information of the .mobileprovision file, confirming that the certificate information inside matches the certificate used for packaging. If mismatched, regenerate the profile and select the correct certificate.

Signature Corruption Caused by Re-signing

If an IPA has been unpacked and modified (e.g., code obfuscation or resource replacement) and then re-signed with another certificate, the signature chain may be broken. Especially after code obfuscation, the executable’s signature becomes invalid.

After obfuscation tools like IpaGuard process the IPA, the signing process needs to be redone. If you used a development certificate for testing after obfuscation, remember to switch to a distribution certificate and re-sign before release. The certificate types for the new signing must not be mixed.

Missing Private Key

Signing requires two things: the certificate (public key) and the corresponding private key. If only the P12 certificate file is imported on the computer without the corresponding private key, signature verification will fail. When regenerating a certificate in Appuploader, the private key is automatically included, and the generated P12 file should be properly saved. When operating on a different computer, you need to import the original P12 file used to generate the certificate into the tool, rather than regenerating a certificate with the same name.

Re-upload with Appuploader

After fixing the signing issue, increment the version number and re-package. In Appuploader’s submission/upload interface, select the new IPA, fill in the app-specific password, and click Upload. After successful upload, wait 10-30 minutes for the build version to appear. If the Invalid Signature error persists, check the specific error code in the email. Apple will send an email to the developer account’s mailbox after an upload failure, indicating the specific signing issue.

Other Possible Causes

An app icon containing an alpha channel or a Bundle ID mismatch can also cause signature verification to fail, and such errors usually have more specific descriptions. A Bundle ID mismatch typically results in “No suitable application records found”, while icon issues prompt ITMS-90717.