diff --git a/pyproject.toml b/pyproject.toml
index 7a1e099..1d64d50 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,7 +37,7 @@ dependencies = [
     "imutils>=0.5.4",
     "ipympl>=0.9.1",
     "ipywidgets>=7.7.1",
-    "matplotlib>=3.5.1",
+    "matplotlib>=3.5.1, <3.10.0",
     "numpy>=1.21.6",
     "opencv-python>=4.8.1.78",
     "pynxtools-mpes>=0.2.1",
diff --git a/src/specsscan/metadata.py b/src/specsscan/metadata.py
index f7bd4e7..de9425b 100644
--- a/src/specsscan/metadata.py
+++ b/src/specsscan/metadata.py
@@ -194,7 +194,7 @@ def fetch_elab_metadata(self, scan: int, metadata: dict) -> dict:
                     if val["value"] is not None and val["value"] != "" and val["value"] != ["None"]:
                         try:
                             metadata["elabFTW"][category][key] = float(val["value"])
-                        except ValueError:
+                        except (ValueError, TypeError):
                             metadata["elabFTW"][category][key] = val["value"]
 
         # group beam profiles: