diff --git a/notebooks/LPD/LPDChar_Darks_NBC.ipynb b/notebooks/LPD/LPDChar_Darks_NBC.ipynb
index 035a34435cd0c89d36d3e81a4a973909d7345522..d5ec25f0d349e1661c71e34df6f07f87cc2ea844 100644
--- a/notebooks/LPD/LPDChar_Darks_NBC.ipynb
+++ b/notebooks/LPD/LPDChar_Darks_NBC.ipynb
@@ -250,7 +250,8 @@
     "        tids_by_cell_pattern.setdefault(tuple(cid_arr), []).append(tid)\n",
     "\n",
     "    if not tids_by_cell_pattern:\n",
-    "        raise ValueError(\"No cell ID patterns were found.\")\n",
+    "        warning(\"No cell ID patterns were found.\")\n",
+    "        return None, None\n",
     "\n",
     "    most_common, sel_tids = max(tids_by_cell_pattern.items(), key=lambda p: len(p[1]))\n",
     "    \n",
@@ -275,6 +276,8 @@
     "    run = RunDirectory(run_path, parallelize=False)\n",
     "    det_source = run[source_name.format(karabo_id, channel)]\n",
     "    cellid_pattern, train_ids = find_common_cell_pattern(det_source)\n",
+    "    if cellid_pattern is None:\n",
+    "        return None, None, None, None, None, None, None, None\n",
     "    data = det_source['image.data'][by_id[train_ids]]\n",
     "    cell_ids = det_source['image.cellId'][by_id[train_ids]]\n",
     "\n",