diff --git a/backend/src/services/importResolvers.ts b/backend/src/services/importResolvers.ts
index fab71e5..f8bfd10 100644
--- a/backend/src/services/importResolvers.ts
+++ b/backend/src/services/importResolvers.ts
@@ -536,13 +536,15 @@ export function extractPageMetadata(html: string, pageHost: string): ImportedPag
   return meta;
 }
 
-/** The profile named in the URL hash (if the design has it), then the default, then the first. */
-function makerworldInstanceIdFromNextData(data: unknown, requestedInstanceId: string | null): string | null {
+/** The profile named in the URL hash (if the design has it), then the default (if the design still
+ *  has it), then the first. MakerWorld can leave `defaultInstanceId` pointing at a deleted profile,
+ *  whose download answers 403 "The client does not have access rights to the content." */
+export function makerworldInstanceIdFromNextData(data: unknown, requestedInstanceId: string | null): string | null {
   const design = getPath(data, "props", "pageProps", "design") as Record<string, unknown> | undefined;
   if (!design) return null;
   if (requestedInstanceId && makerworldDesignHasInstance(design, requestedInstanceId)) return requestedInstanceId;
   const defaultInstance = design.defaultInstanceId;
-  if (defaultInstance) return String(defaultInstance);
+  if (defaultInstance && makerworldDesignHasInstance(design, String(defaultInstance))) return String(defaultInstance);
   const instances = design.instances;
   if (Array.isArray(instances)) {
     for (const inst of instances) {
diff --git a/backend/tests/makerworldInstanceSelection.test.ts b/backend/tests/makerworldInstanceSelection.test.ts
new file mode 100644
index 0000000..9153187
--- /dev/null
+++ b/backend/tests/makerworldInstanceSelection.test.ts
@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import { makerworldInstanceIdFromNextData } from "../src/services/importResolvers";
+
+function nextData(design: Record<string, unknown>) {
+  return { props: { pageProps: { design } } };
+}
+
+describe("makerworldInstanceIdFromNextData", () => {
+  const design = { defaultInstanceId: 2, instances: [{ id: 1 }, { id: 2 }, { id: 3 }] };
+
+  it("takes the link's profile, else the default, else the first", () => {
+    expect(makerworldInstanceIdFromNextData(nextData(design), "3")).toBe("3");
+    expect(makerworldInstanceIdFromNextData(nextData(design), null)).toBe("2");
+    expect(makerworldInstanceIdFromNextData(nextData(design), "999")).toBe("2");
+    expect(makerworldInstanceIdFromNextData(nextData({ instances: [{ id: 7 }] }), null)).toBe("7");
+  });
+
+  // Seen on MakerWorld model 1106505: defaultInstanceId 1102432, but the only profile is 1113369.
+  // Downloading the stale default answers 403 "The client does not have access rights to the content."
+  it("skips a default that is no longer one of the design's profiles", () => {
+    const stale = { defaultInstanceId: 1102432, instances: [{ id: 1113369 }] };
+    expect(makerworldInstanceIdFromNextData(nextData(stale), null)).toBe("1113369");
+  });
+
+  it("answers null without a design or profiles", () => {
+    expect(makerworldInstanceIdFromNextData({}, null)).toBeNull();
+    expect(makerworldInstanceIdFromNextData(nextData({ defaultInstanceId: 5, instances: [] }), null)).toBeNull();
+  });
+});
diff --git a/extension/src/content/makerworld/pageData.ts b/extension/src/content/makerworld/pageData.ts
index 847f7fa..334f20e 100644
--- a/extension/src/content/makerworld/pageData.ts
+++ b/extension/src/content/makerworld/pageData.ts
@@ -100,12 +100,16 @@ export async function loadMakerworldCollectionTotal(pageUrl: string): Promise<nu
   );
 }
 
-/** The requested profile (if the design has it), then the default, then the first. */
+/** The requested profile (if the design has it), then the default (if the design still has it),
+ *  then the first. MakerWorld can leave `defaultInstanceId` pointing at a profile that was since
+ *  deleted, and asking for that one's download answers 403 "The client does not have access rights
+ *  to the content." */
 export function pickMakerworldInstanceId(design: MakerworldDesign, requestedInstanceId: string | null): string | null {
   const instances = Array.isArray(design.instances) ? design.instances.filter((inst) => inst && inst.id) : [];
-  if (requestedInstanceId && instances.some((inst) => String(inst.id) === requestedInstanceId))
-    return requestedInstanceId;
-  if (design.defaultInstanceId) return String(design.defaultInstanceId);
+  const has = (id: string) => instances.some((inst) => String(inst.id) === id);
+  if (requestedInstanceId && has(requestedInstanceId)) return requestedInstanceId;
+  const defaultId = design.defaultInstanceId ? String(design.defaultInstanceId) : null;
+  if (defaultId && has(defaultId)) return defaultId;
   return instances.length ? String(instances[0].id) : null;
 }