diff --git a/components/canvas/__tests__/use-canvas-drop.test.tsx b/components/canvas/__tests__/use-canvas-drop.test.tsx
index 7965139..1ebf676 100644
--- a/components/canvas/__tests__/use-canvas-drop.test.tsx
+++ b/components/canvas/__tests__/use-canvas-drop.test.tsx
@@ -7,6 +7,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import type { Id } from "@/convex/_generated/dataModel";
 import { CANVAS_NODE_DND_MIME } from "@/lib/canvas-connection-policy";
 import { NODE_DEFAULTS } from "@/lib/canvas-utils";
+import { toast } from "@/lib/toast";
 import { useCanvasDrop } from "@/components/canvas/use-canvas-drop";
 
 vi.mock("@/lib/toast", () => ({
@@ -66,8 +67,10 @@ function HookHarness({
 describe("useCanvasDrop", () => {
   let container: HTMLDivElement | null = null;
   let root: Root | null = null;
+  let consoleErrorSpy: ReturnType<typeof vi.spyOn>;
 
   beforeEach(() => {
+    consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => undefined);
     vi.stubGlobal("fetch", vi.fn(async () => ({
       ok: true,
       json: async () => ({ storageId: "storage-1" }),
@@ -80,6 +83,7 @@ describe("useCanvasDrop", () => {
   afterEach(async () => {
     latestHandlersRef.current = null;
     vi.clearAllMocks();
+    consoleErrorSpy.mockRestore();
     vi.unstubAllGlobals();
     if (root) {
       await act(async () => {
@@ -198,4 +202,110 @@ describe("useCanvasDrop", () => {
       "node-image",
     );
   });
+
+  it("creates a node from a JSON payload drop", async () => {
+    const runCreateNodeOnlineOnly = vi.fn(async () => "node-video");
+    const syncPendingMoveForClientRequest = vi.fn(async () => undefined);
+
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+
+    await act(async () => {
+      root?.render(
+        <HookHarness
+          runCreateNodeOnlineOnly={runCreateNodeOnlineOnly}
+          syncPendingMoveForClientRequest={syncPendingMoveForClientRequest}
+        />,
+      );
+    });
+
+    await act(async () => {
+      await latestHandlersRef.current?.onDrop({
+        preventDefault: vi.fn(),
+        clientX: 90,
+        clientY: 75,
+        dataTransfer: {
+          getData: vi.fn((type: string) =>
+            type === CANVAS_NODE_DND_MIME
+              ? JSON.stringify({
+                  type: "video",
+                  data: {
+                    assetId: "asset-42",
+                    label: "Clip",
+                  },
+                })
+              : "",
+          ),
+          files: [],
+        },
+      } as unknown as React.DragEvent);
+    });
+
+    expect(runCreateNodeOnlineOnly).toHaveBeenCalledWith({
+      canvasId: "canvas-1",
+      type: "video",
+      positionX: 90,
+      positionY: 75,
+      width: NODE_DEFAULTS.video.width,
+      height: NODE_DEFAULTS.video.height,
+      data: {
+        ...NODE_DEFAULTS.video.data,
+        assetId: "asset-42",
+        label: "Clip",
+        canvasId: "canvas-1",
+      },
+      clientRequestId: "req-1",
+    });
+    expect(syncPendingMoveForClientRequest).toHaveBeenCalledWith("req-1", "node-video");
+  });
+
+  it("shows an upload failure toast when the dropped file upload fails", async () => {
+    const generateUploadUrl = vi.fn(async () => "https://upload.test");
+    const runCreateNodeOnlineOnly = vi.fn(async () => "node-image");
+    const syncPendingMoveForClientRequest = vi.fn(async () => undefined);
+    const file = new File(["image-bytes"], "photo.png", { type: "image/png" });
+
+    vi.stubGlobal(
+      "fetch",
+      vi.fn(async () => ({
+        ok: false,
+        json: async () => ({ storageId: "storage-1" }),
+      })),
+    );
+
+    container = document.createElement("div");
+    document.body.appendChild(container);
+    root = createRoot(container);
+
+    await act(async () => {
+      root?.render(
+        <HookHarness
+          generateUploadUrl={generateUploadUrl}
+          runCreateNodeOnlineOnly={runCreateNodeOnlineOnly}
+          syncPendingMoveForClientRequest={syncPendingMoveForClientRequest}
+        />,
+      );
+    });
+
+    await act(async () => {
+      await latestHandlersRef.current?.onDrop({
+        preventDefault: vi.fn(),
+        clientX: 240,
+        clientY: 180,
+        dataTransfer: {
+          getData: vi.fn(() => ""),
+          files: [file],
+        },
+      } as unknown as React.DragEvent);
+    });
+
+    expect(runCreateNodeOnlineOnly).not.toHaveBeenCalled();
+    expect(syncPendingMoveForClientRequest).not.toHaveBeenCalled();
+    expect(consoleErrorSpy).toHaveBeenCalledWith(
+      "Failed to upload dropped file:",
+      expect.any(Error),
+    );
+    expect(toast.error).toHaveBeenCalledWith("canvas.uploadFailed", "Upload failed");
+  });
 });
diff --git a/components/canvas/canvas.tsx b/components/canvas/canvas.tsx
index d2e457a..8f755ce 100644
--- a/components/canvas/canvas.tsx
+++ b/components/canvas/canvas.tsx
@@ -100,7 +100,6 @@ function CanvasInner({ canvasId }: CanvasInnerProps) {
   const [nodes, setNodes] = useState<RFNode[]>([]);
   const [edges, setEdges] = useState<RFEdge[]>([]);
   const edgesRef = useRef(edges);
-  edgesRef.current = edges;
   const deletingNodeIds = useRef<Set<string>>(new Set());
 
   const {
@@ -148,7 +147,6 @@ function CanvasInner({ canvasId }: CanvasInnerProps) {
 
   // ─── Future hook seam: render composition + shared local flow state ─────
   const nodesRef = useRef<RFNode[]>(nodes);
-  nodesRef.current = nodes;
 
   const [scissorsMode, setScissorsMode] = useState(false);
   const [scissorStrokePreview, setScissorStrokePreview] = useState<
@@ -237,7 +235,18 @@ function CanvasInner({ canvasId }: CanvasInnerProps) {
   }, [scissorsMode, navTool]);
 
   const scissorsModeRef = useRef(scissorsMode);
-  scissorsModeRef.current = scissorsMode;
+
+  useEffect(() => {
+    edgesRef.current = edges;
+  }, [edges]);
+
+  useEffect(() => {
+    nodesRef.current = nodes;
+  }, [nodes]);
+
+  useEffect(() => {
+    scissorsModeRef.current = scissorsMode;
+  }, [scissorsMode]);
 
   // Drag-Lock: während des Drags kein Convex-Override
   const isDragging = useRef(false);
@@ -326,7 +335,15 @@ function CanvasInner({ canvasId }: CanvasInnerProps) {
 
   useEffect(() => {
     if (isDragging.current) return;
-    setNodes((nds) => withResolvedCompareData(nds, edges));
+    let cancelled = false;
+    queueMicrotask(() => {
+      if (!cancelled) {
+        setNodes((nds) => withResolvedCompareData(nds, edges));
+      }
+    });
+    return () => {
+      cancelled = true;
+    };
   }, [edges]);
 
   const {