This error is reaction on new build created and uploaded to AppStore with new project but same bundleId/displayName/signingInfo.
Here is the scenario with symbolic values to explain it better:
Build #1 (Version 1.0)
- project: P1
- Bundle id: com.some.app
- Display name: My App
- Signing info: TeamX, CertificateX (automatic signing)
I had to move the app to new project with completely new targets/configs/sources but same app metadata.
Build #2 (Version 1.0)
- project: P2 (new)
- Bundle id: com.some.app
- Display name: My App
- Signing info: TeamX, CertificateX (automatic signing)
So you can see that all is changed but the important app metadata (BundleId, DisplayName, Signing info) remained the same.
Yet the upload of build 2 results with: ITMS-90129: The bundle uses a bundle name or display name that is already taken
Note that the Build #2 showed in "AppStoreConnect / TestFlight / iOS Builds / Version 1.0" for a few seconds as "Processing" but than disapeared with the error. Thus Apple tries to add the new build #2 it to proper application version but than for some reason it thinks that Build #1 and #2 comes from different applications.
Any thoughts why?