Xcode upload failed with error "asset catalog failed to compile" troubleshooting

TL;DR

Open the asset catalog compile log, find the first invalid asset, and fix that entry: usually a missing image file, a malformed app icon set, duplicate entries, or an image with an unsupported format or colour profile. Correct or remove the offending asset, clean the build folder, and re-archive. The compiler stops at the first bad asset, so fix iteratively until the catalog compiles cleanly on its own.

asset catalog failed to compile - Xcode upload

Use this when

• Archive or upload fails in the asset catalog compile step.
• App icons or launch images were replaced recently.
• The error appears in CI where a generated asset step runs before archiving.

Not for this skill when

• The failure is a codesign or profile error later in the same log. Fix the first failing step only if it is the catalog.
• The catalog compiles locally but not in CI. Compare Xcode versions and generated asset scripts between environments.

Steps

1. Build with the detailed log visible and scroll to the first asset catalog error, which names the catalog, the asset and the reason. Verify: the exact failing asset and message are identified
2. Open that asset set in Xcode and check for missing file references shown in red, empty slots required for the app icon, or images whose actual dimensions differ from their declared size. Verify: the concrete defect in the set is found and corrected or the asset is replaced
3. Check for duplicate asset names across catalogs and for two app icon sets both marked as the targets icon. Verify: each asset name is unique and exactly one primary app icon set is assigned
4. Validate suspicious images by opening them in an image tool and re-exporting as standard PNG or sRGB if the log mentions format or profile problems. Verify: the re-exported file replaces the bad one and opens cleanly
5. Compile the catalog alone using the actool command from the log, or a quick archive build, before running the full upload. Verify: actool finishes with no errors on the catalog
6. Archive and upload again. Verify: the archive succeeds and the build reaches processing in App Store Connect
7. Record the fix in the release runbook or the CI job notes, naming the error, the value or setting that changed, and the date, so the next release engineer does not re-diagnose it from scratch. Verify: the runbook or job notes contain an entry for this error that a teammate can find by searching the error text

Why it happens

The asset catalog compiler, actool, validates every image set strictly at archive time: file presence, dimensions, colour space and icon completeness. A single bad slot fails the whole catalog, and because debug builds sometimes skip full catalog compilation optimisations, the defect can hide until the release archive. Generated assets from design tools with exotic profiles are a frequent source.

In practice this failure is rarely a one-off. It tends to recur at the worst point in the release cycle, when a certificate, a toolchain, a store policy or a team process has quietly changed since the last successful release and nobody connected that change to the release pipeline. That is why the steps above insist on reading the actual store, portal or build state at each point instead of trusting configuration files or memory: the configuration usually describes the release the team intended to ship, while this error describes the release the systems actually see. Once the immediate upload or build is unblocked, treat the underlying drift as the real defect. Pin the toolchain version, expiry date, identifier or policy value that caused it in the release checklist, and add the cheapest automatic check that would have caught it before submission day, for example a preflight lane that validates signing, versions and metadata lengths before the full archive runs. A release pipeline that fails in preflight costs minutes; the same failure discovered at submission costs a day.

Variants and edge cases

asset catalog failed to compile Xcode archive

Archive phrasing; read the first actool error. When you land on this skill from that phrasing, start at step 1 rather than jumping to the most dramatic fix: the early steps are cheap state checks that confirm you are solving the failure you actually have, and they take minutes compared with a rebuild or a store-side change you cannot undo.

actool error app icon missing sizes fix

Icon-specific variant; fill every required icon slot at exact dimensions. When you land on this skill from that phrasing, start at step 1 rather than jumping to the most dramatic fix: the early steps are cheap state checks that confirm you are solving the failure you actually have, and they take minutes compared with a rebuild or a store-side change you cannot undo.

Edge case: CarPlay and alternate icons

Alternate icon sets are validated too. A broken alternate icon fails the archive even if the primary icon is perfect. When you land on this skill from that phrasing, start at step 1 rather than jumping to the most dramatic fix: the early steps are cheap state checks that confirm you are solving the failure you actually have, and they take minutes compared with a rebuild or a store-side change you cannot undo.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_P8Frt3X0qqVOL-YXuPRWgA