diff --git a/app/ui/features/upscale/index.js b/app/ui/features/upscale/index.js
index d8b90483..ba0b9237 100644
--- a/app/ui/features/upscale/index.js
+++ b/app/ui/features/upscale/index.js
@@ -35,21 +35,23 @@ export default {
     }
 
     async function run(media, pressed = false) {
-      // RTX only counts when this machine has it on right now: a project saved elsewhere may still say "rtx"
-      const rtxHere = rtxOn() && await app.api.upscaleModels().then((r) => Boolean(r.rtx)).catch(() => false);
-      const model = rtxOn() ? (rtxHere ? RTX : "") : p.pref("upscaleModel", "");
       if (!media || media.subfolder === UPSCALED) return;                    // never upscale twice
-      if (!model) return pressed ? suggest() : c.toast.warn({ text: "Upscale: pick a model or NVIDIA RTX Super Resolution in Settings ▸ Editor." });
       const key = keyOf(media), pid = p.project.id;
       if (busy.has(key)) return;
-      busy.add(key); draw(); c.toast.info({ text: `Upscaling with ${model}…` });
+      busy.add(key); draw();
       try {
+        // RTX only counts when this machine has it on right now: a project saved elsewhere may still say "rtx"
+        if (rtxOn() && !(await app.api.upscaleModels().then((r) => Boolean(r.rtx)).catch(() => false)))
+          return void c.toast.warn({ text: `${RTX} is not available on this machine (or is switched off in Settings ▸ Modules). Pick Upscale model as the Engine in Settings ▸ Editor.` });
+        const model = rtxOn() ? RTX : p.pref("upscaleModel", "");
+        if (!model) return void (pressed ? suggest() : c.toast.warn({ text: "Upscale: pick a model or NVIDIA RTX Super Resolution in Settings ▸ Editor." }));
+        c.toast.info({ text: `Upscaling with ${model}…` });
         const out = await upscale(app.api, media, model, undefined, rtxOn() ? rtxOpts() : undefined);
         const swapped = await p.editFor(pid, (pr) => swap(pr, media, out) > 0);
         if (!swapped) c.toast.warn({ text: "Upscaled, but that render was replaced meanwhile, so nothing was swapped." });
         else c.toast.good({ text: "Upscaled: the render now plays the larger video." });
       } catch (err) { c.toast.warn({ text: `Upscale failed: ${err.message}` }); }
-      busy.delete(key); draw();
+      finally { busy.delete(key); draw(); }
     }
 
     function draw() {
diff --git a/conftest.py b/conftest.py
index d0b46cee..bacfb569 100644
--- a/conftest.py
+++ b/conftest.py
@@ -32,6 +32,13 @@ def _comfyui_root():
 COMFYUI = _comfyui_root()
 
 
+@pytest.fixture(autouse=True)
+def _own_addons_file(tmp_path, monkeypatch):
+    """A developer's own addons.json must not decide what a test sees."""
+    from core import config
+    monkeypatch.setattr(config, "ADDONS_FILE", tmp_path / "addons.json")
+
+
 @pytest.fixture(scope="session")
 def comfyui():
     """ComfyUI's source tree on sys.path, or skip.
diff --git a/core/addons.py b/core/addons.py
index 7448cbb2..e51a73b4 100644
--- a/core/addons.py
+++ b/core/addons.py
@@ -81,7 +81,7 @@ def _wanted(data) -> set:
 def enabled(addon_id: str) -> bool:
     """Wanted and installed: the only state in which code may use the add-on."""
     a = _BY_ID.get(addon_id)
-    return bool(a) and addon_id in _wanted(_read()) and _present(a)
+    return bool(a) and a["offered"]() and addon_id in _wanted(_read()) and _present(a)
 
 
 def listing() -> list[dict]:
diff --git a/core/tests/test_addons.py b/core/tests/test_addons.py
index 2dd086c6..b43c5080 100644
--- a/core/tests/test_addons.py
+++ b/core/tests/test_addons.py
@@ -111,3 +111,11 @@ def test_the_routes_list_and_switch(comfyui, here):
     assert bad == 400
     assert next(a["state"] for a in ok["addons"] if a["id"] == "camera") == "pending"
     assert json.loads(config.ADDONS_FILE.read_text())["wanted"] == ["camera"]
+
+
+def test_an_add_on_this_machine_cannot_run_is_not_enabled_even_if_wanted_and_installed(here, monkeypatch):
+    here.add("nvidia_vsr")
+    addons.set_wanted("nvidia_vsr", True)
+    assert addons.enabled("nvidia_vsr")
+    monkeypatch.setitem(addons._BY_ID["nvidia_vsr"], "offered", lambda: False)     # the folder moved to a machine without the card
+    assert not addons.enabled("nvidia_vsr")