test

src/pybamm/util.py

@@ -94,10 +94,16 @@ def __getitem__(self, key):
                 ) from error
             best_matches = self.get_best_matches(key)
             for k in best_matches:
-                if key in k and k.endswith("]"):
+                if key in k and k.endswith("]") and not key.endswith("]"):
                     raise KeyError(
                         f"'{key}' not found. Use the dimensional version '{k}' instead."
                     ) from error
+                elif key in k and (
+                    k.startswith("Primary") or k.startswith("Secondary")
+                ):
+                    raise KeyError(
+                        f"'{key}' not found. If you are using a composite model, you may need to use {k} instead. Otherwise, best matches are {best_matches}"
+                    ) from error
             raise KeyError(
                 f"'{key}' not found. Best matches are {best_matches}"
             ) from error