We are trying to upload the first Apple-hosted Managed Background Assets pack for our macOS app, but Transporter rejects the asset pack ID during upload. App details: App name: DistillApp Apple ID: 6760288806 Bundle ID: cn.rkbkosp.DistillApp Asset pack ID: distill.pipeline.zh-baseline Platform: macOS Transporter: 1.4 Xcode: 26.2 macOS: 26.3.1 What we see in Transporter: Apple ID: 6760288806 App Name: DistillApp App Bundle ID: cn.rkbkosp.DistillApp No background assets found. And when we try to upload the first asset pack, Transporter fails with: 获取 Apple ID “6760288806”的资源包列表失败。 (-19243) There is an error with a URL parameter (400) Found invalid values: distill.pipeline.zh-baseline What we have already confirmed locally: The app resolves correctly in Transporter, so the Apple ID and bundle ID appear to be correct. The app Info.plist includes: BAHasManagedAssetPacks = YES BAUsesAppleHosting = YES BAAppGroupID = 8U6DAJ62JT.group.cn.rkbkosp.DistillApp.assets The asset pack manifest uses: assetPackID = distill.pipeline.zh-baseline This is intended to be the first Apple-hosted background asset pack for the app. Our understanding is that No background assets found is expected before the first successful upload, so the actual problem seems to be that Transporter/App Store Connect refuses to accept the initial asset pack ID. Questions: Has anyone seen Transporter reject the first Apple-hosted background asset pack for an app with -19243 and 400 invalid values? Does the first Managed Background Assets upload require any additional App Store Connect state beyond having BAHasManagedAssetPacks and BAUsesAppleHosting in the app? Does the app need a newly processed build in App Store Connect after enabling those plist keys before the first asset pack upload will work? Is there any known issue in Transporter 1.4 or App Store Connect for first-time Apple-hosted MBA uploads on macOS apps? If useful, I can also share the exact asset pack manifest and a redacted upload log.