diff --git a/src/backend/services/vision_service.py b/src/backend/services/vision_service.py
index 8b74e2d..400472f 100644
--- a/src/backend/services/vision_service.py
+++ b/src/backend/services/vision_service.py
@@ -261,7 +261,15 @@ def store_recipe_folder(
     is left untouched (immutable: other task versions may reference it).
     """
     canonical = json.dumps(recipe, sort_keys=True, separators=(",", ":"))
-    digest = hashlib.sha256(canonical.encode("utf-8")).hexdigest()[:16]
+    # Il digest copre anche i file (path ordinato + sha256 del contenuto): la
+    # stessa ricetta con file diversi (es. primo upload senza il DXF) deve dare
+    # una cartella diversa, altrimenti quella incompleta resterebbe per sempre
+    # perche' immutabile (#46).
+    h = hashlib.sha256(canonical.encode("utf-8"))
+    for rel in sorted(files):
+        h.update(b"\0" + rel.encode("utf-8") + b"\0")
+        h.update(hashlib.sha256(files[rel]).digest())
+    digest = h.hexdigest()[:16]
     relative = f"vision/recipes/{task_id}/{digest}"
     folder = settings.upload_path / relative
     if folder.exists():
diff --git a/src/backend/tests/test_vision_recipe_upload.py b/src/backend/tests/test_vision_recipe_upload.py
index ed922fb..6a7262e 100644
--- a/src/backend/tests/test_vision_recipe_upload.py
+++ b/src/backend/tests/test_vision_recipe_upload.py
@@ -263,3 +263,20 @@ async def test_copy_on_write_carries_recipe_dir(client, db_session, maker_user):
     version, new_task, _ = await _current_task_and_subtask(db_session, recipe.id)
     assert version.version_number == 2
     assert new_task.vision_recipe_dir == "vision/recipes/1/abc" and new_task.vision_json == RECIPE
+
+
+@pytest.mark.asyncio
+async def test_retry_with_missing_file_then_complete_succeeds(
+    client, db_session, maker_user, monkeypatch,
+):
+    # worker finto: ok solo se il DXF esiste nella cartella della ricetta
+    async def fake(graph, recipe_dir):
+        present = (settings.upload_path / recipe_dir / "dxf" / "part.dxf").is_file()
+        return {"ok": present, "errors": [] if present else ["dxf missing"], "outputs": OUTPUTS}
+    monkeypatch.setattr("src.backend.services.vision_service.validate_recipe", fake)
+    task, _ = await make_task(db_session, maker_user)
+
+    first = await upload(client, maker_user, task, files=[])
+    assert first.status_code == 422
+    second = await upload(client, maker_user, task, files=GOOD_FILES)
+    assert second.status_code == 200, second.text