diff --git a/packages/core/stubs/audio-fx-runtime-entry.ts b/packages/core/stubs/audio-fx-runtime-entry.ts
index 81f8e5f035..d6a78b9439 100644
--- a/packages/core/stubs/audio-fx-runtime-entry.ts
+++ b/packages/core/stubs/audio-fx-runtime-entry.ts
@@ -81,6 +81,11 @@ async function render(
   const chain: HfAudioFxChain = parseAudioFxChain(chainJson);
   const channels = Math.max(1, planes.length);
   const frames = planes[0]?.length ?? 0;
+  // Nothing to process, and `new OfflineAudioContext(ch, 0, rate)` throws — an
+  // error the render treats as fatal. applyAudioFxChain screens empty tracks
+  // out before they reach the browser; this is the same guard at the point the
+  // constructor would actually blow up.
+  if (frames === 0) return planes;
   const parsedAutomation = automationJson
     ? resolveAutomation(parseAutomation(automationJson), chain)
     : null;
diff --git a/packages/engine/src/services/audioFxRender.test.ts b/packages/engine/src/services/audioFxRender.test.ts
index 6b07f35c3a..553333ee85 100644
--- a/packages/engine/src/services/audioFxRender.test.ts
+++ b/packages/engine/src/services/audioFxRender.test.ts
@@ -253,3 +253,25 @@ describe("browser render", () => {
     expect(readWav(outPath).samples.length).toBeGreaterThan(0);
   }, 180_000);
 });
+
+/**
+ * ffmpeg exits 0 and writes a structurally valid but EMPTY wav whenever a
+ * clip's trim starts past the end of its source (`-ss 10 -t 5` on a 2 s file).
+ * That track used to reach `new OfflineAudioContext(ch, 0, rate)`, which throws
+ * — and the error travels past the mixer's per-track failure collector, so one
+ * mis-set `data-media-start` took the whole render down.
+ */
+describe("an empty track", () => {
+  it("is handed back untouched rather than failing the render", async () => {
+    const input = join(dir, "empty.wav");
+    writeWav(input, new Float32Array(0), SR);
+    const output = join(dir, "out.wav");
+
+    // Returns the input path, the same contract as a chain with nothing enabled
+    // — and without paying for a browser to decide it.
+    await expect(
+      applyAudioFxChain(input, chainOf("peaking"), output, { trackId: "t" }),
+    ).resolves.toBe(input);
+    expect(existsSync(output)).toBe(false);
+  });
+});
diff --git a/packages/engine/src/services/audioFxRender.ts b/packages/engine/src/services/audioFxRender.ts
index 1d53156621..5e9f62c0d3 100644
--- a/packages/engine/src/services/audioFxRender.ts
+++ b/packages/engine/src/services/audioFxRender.ts
@@ -194,6 +194,14 @@ export async function applyAudioFxChain(
 
   const { samples, sampleRate, channels } = readWav(inputWav);
   const planes = deinterleave(samples, channels);
+  // An empty track has nothing to process — and an OfflineAudioContext of zero
+  // length throws, which is fatal for the WHOLE render rather than this track:
+  // the error travels past the mixer's per-track failure collector. ffmpeg
+  // writes an empty but structurally valid WAV whenever a clip's trim starts
+  // past the end of its source, so one mis-set `data-media-start` used to take
+  // the render down. Guarded here as well as in the runtime so an empty track
+  // never costs a browser.
+  if ((planes[0]?.length ?? 0) === 0) return inputWav;
 
   // Audio processing needs no GPU or special capture mode; a plain sandboxed
   // browser is enough, and the lease pool reuses one across tracks.