What causes an Unreal packaging failure?

The cook or build step failed — usually a missing platform SDK, a redirector or missing asset reference, a shader compile error, or a C++ compile failure that the generic message hides.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix “Packaging failed” in Unreal Engine

Quick answer: Open the packaging log and find the first error line, then fix what it names: install the platform SDK, resolve missing or redirected assets, fix shader or code errors.

“Packaging failed” is a summary; the cause is one specific line in a long log. Reading it turns a vague failure into a precise fix. Here is how to find and resolve the usual ones.

How to fix it

1. Find the first error in the log

Open the full packaging log (Window, Output Log, or the saved log file) and search for the first Error line. Later errors are often cascades; the first one is the cause.

2. Install or fix the platform SDK

Packaging for Android, iOS, or consoles needs the matching SDK and toolchain. A missing or mismatched SDK fails the cook. Run the platform setup and confirm the SDK version Unreal expects.

3. Resolve missing assets and code errors

Fix up redirectors, delete references to deleted assets, and clear shader or C++ compile errors. A cook fails if it cannot load a referenced asset or compile a shader the content uses.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unreal Engine error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.