diff --git a/000409/IBL/bwm_usage_notebook.ipynb b/000409/IBL/bwm_usage_notebook.ipynb
index cbfe116..76a1d10 100644
--- a/000409/IBL/bwm_usage_notebook.ipynb
+++ b/000409/IBL/bwm_usage_notebook.ipynb
@@ -2277,6 +2277,31 @@
     }
    ],
    "source": [
+    "# Workaround: brainglobe-atlasapi 2.3.1 fetches its atlas-version manifest\n",
+    "# from a Colab-unfriendly S3 endpoint that returns 403 for some Colab IPs.\n",
+    "# Pre-seed the cache so BrainGlobeAtlas() below can find a version manifest\n",
+    "# even when the live fetch fails. See https://github.com/brainglobe/brainglobe-atlasapi/issues/738\n",
+    "from pathlib import Path\n",
+    "import urllib.request\n",
+    "\n",
+    "_bg_dir = Path.home() / \".brainglobe\"\n",
+    "_manifest_url = (\n",
+    "    \"https://brainglobe.s3.us-west-2.amazonaws.com/atlas/atlases/last_versions.conf\"\n",
+    ")\n",
+    "try:\n",
+    "    _manifest = urllib.request.urlopen(_manifest_url, timeout=20).read().decode()\n",
+    "except Exception as _e:  # noqa: BLE001\n",
+    "    print(f\"Couldn't reach brainglobe manifest ({_e}); writing a minimal fallback.\")\n",
+    "    _manifest = \"[atlases]\\nallen_mouse_25um = 3.0\\n\"\n",
+    "\n",
+    "# Write to both the V1 and V2 cache paths so whichever brainglobe-atlasapi\n",
+    "# code path reads from disk finds the file.\n",
+    "for _p in (_bg_dir / \"last_versions.conf\",\n",
+    "           _bg_dir / \"brainglobe-atlasapi\" / \"atlases\" / \"last_versions.conf\"):\n",
+    "    _p.parent.mkdir(parents=True, exist_ok=True)\n",
+    "    if not _p.exists():\n",
+    "        _p.write_text(_manifest)\n",
+    "\n",
     "import matplotlib.pyplot as plt\n",
     "import numpy as np\n",
     "from brainglobe_atlasapi import BrainGlobeAtlas\n",