Source Link

Reorganise your art folder, and every Reimport button in the project dies at once.

Unreal writes the source file path onto every asset it imports. Move the raw FBX tree, rename a folder, or open the project on a different machine, and all of those paths go stale together. Reimport stops working project-wide.

There is no built-in way to fix it in bulk. The property is read-only in the details panel, and it lives on a sub-object that Bulk Edit via Property Matrix cannot reach, so the options have always been opening assets one at a time or writing your own Python. The Epic forum thread asking for this opened in October 2015; the first real answer, a user's own script, arrived in January 2026.

Source Link is that missing bulk operation.

What it does

Finds every broken link without opening a single asset. Every source path in your project is already in the Asset Registry as a tag, and Source Link reads them there. A 20,000 asset project answers in seconds, and the report prints "Assets loaded to scan: 0" as a measured number rather than a marketing claim. Only the assets it actually repairs are ever loaded.

Works out where the files went. Point it at the art tree's new home. For each missing file it scores every candidate with the same name by how much of the old folder path still agrees, and by the MD5 the engine recorded at import, which identifies the file no matter how far it moved.

Refuses to guess. When two files are equally good answers, Source Link reports the row as ambiguous, lists both with their scores, and writes nothing. A wrong repair is committed and afterwards cannot be told from a right one. That choice stays yours.

Shows you everything first. Every run is a preview and writes a designed HTML sheet: every asset, every source reference, what would change, and the reasoning for each. Applying is a separate, deliberate step.

Fixes the machine-specific paths too. Absolute paths resolve on exactly one computer. Normalise mode rewrites them relative to the package using the engine's own rules, so they survive a teammate opening the project. Off by default, because a tool that quietly rewrites healthy data the first time you run it does not deserve trust with the broken data.

Built for a pipeline, not just a panel

It is a commandlet, so it runs on a build server with no editor window, with distinct exit codes: "your source links have rotted" is a different code from "I could not run", and a scan that examined nothing is never reported as a project with nothing wrong. Files are checked out of source control before they are written.

Honest specifications

Unreal Engine 5.8 on Windows, built and verified against 5.8, which is the only version claimed. Full C++ source included and written to be read. Ships no content and no assets of any kind. 18 automation tests cover the matcher, the registry tag parser, the planner and the report. Repaired references keep the timestamp and MD5 recorded at import.

More Unreal editor tooling from Core Systems Asset Factory at csaf.itch.io