diff --git a/omtra/data/plinder/__init__.py b/omtra/data/plinder/__init__.py
index 2af7801..a206935 100644
--- a/omtra/data/plinder/__init__.py
+++ b/omtra/data/plinder/__init__.py
@@ -118,6 +118,9 @@ def to_xace_mol(self, dense=False) -> MolXACE:
             # very hacky bug fix here
             if xace_dict[k] is None and k in ['fixed_atom_mask', 'fixed_edge_mask']:
                 continue
+            elif xace_dict[k] is None and k not in ['fixed_atom_mask', 'fixed_edge_mask']:
+                raise ValueError(f"{k} is None but not in ['fixed_atom_mask', 'fixed_edge_mask']")
+
 
             if k == 'x':
                 xace_dict[k] = xace_dict[k].float()