diff --git a/plottr/data/datadict.py b/plottr/data/datadict.py
index 01e6491b..845e3e5a 100644
--- a/plottr/data/datadict.py
+++ b/plottr/data/datadict.py
@@ -1010,7 +1010,10 @@ def validate(self) -> bool:
 
         shp = None
         shpsrc = ''
-        for n, v in self.data_items():
+
+        data_items = dict(self.data_items())
+
+        for n, v in data_items.items():
             if type(v['values']) not in [np.ndarray, np.ma.core.MaskedArray]:
                 self[n]['values'] = np.array(v['values'])
 
@@ -1023,6 +1026,17 @@ def validate(self) -> bool:
                     msg += f" {v['values'].shape}, "
                     msg += f"and '{shpsrc}' has {shp}.\n"
 
+            if 'axes' in v:
+                for axis_num, na in enumerate(v['axes']):
+                    # check that the data of the axes matches its use
+                    # if data present
+                    axis_data = data_items[na]['values']
+                    if axis_data.size > 0:
+                        max_step_along_axes = np.max(np.abs(np.diff(data_items[na]['values'],axis=axis_num)))
+                        if max_step_along_axes == 0:
+                            msg += (f"Malformed data: {na} is expected to be {axis_num}th "
+                                     "axis but has no variation along that axis.\n")
+
             if msg != '\n':
                 raise ValueError(msg)
 
@@ -1087,7 +1101,7 @@ def guess_shape_from_datadict(data: DataDict) -> \
 
 def datadict_to_meshgrid(data: DataDict,
                          target_shape: Union[Tuple[int, ...], None] = None,
-                         inner_axis_order: Union[None, List[str]] = None,
+                         inner_axis_order: Union[None, Sequence[str]] = None,
                          use_existing_shape: bool = False) \
         -> MeshgridDataDict:
     """
diff --git a/plottr/node/grid.py b/plottr/node/grid.py
index 261cf9d8..88213aca 100644
--- a/plottr/node/grid.py
+++ b/plottr/node/grid.py
@@ -3,7 +3,6 @@
 
 A node and widget for placing data onto a grid (or not).
 """
-
 from enum import Enum, unique
 
 from typing import Tuple, Dict, Any, List, Optional, Sequence, cast
@@ -490,9 +489,19 @@ def process(
                         inner_axis_order=order,
                     )
                 elif method is GridOption.metadataShape:
-                    dout = dd.datadict_to_meshgrid(
-                        data, use_existing_shape=True
-                    )
+                    try:
+                        dout = dd.datadict_to_meshgrid(
+                            data, use_existing_shape=True
+                        )
+                    except ValueError as err:
+                        if "Malformed data" in str(err):
+                            self.node_logger.warning(
+                                "Shape/Setpoint order does"
+                                " not match data. Falling back to guessing shape"
+                                )
+                            dout = dd.datadict_to_meshgrid(data)
+                        else:
+                            raise err
             except GriddingError:
                 dout = data.expand()
                 self.node_logger.info("data could not be gridded. Falling back "
diff --git a/test/pytest/test_gridder.py b/test/pytest/test_gridder.py
index 026c271f..e2a5dbae 100644
--- a/test/pytest/test_gridder.py
+++ b/test/pytest/test_gridder.py
@@ -93,12 +93,9 @@ def test_set_grid_with_order(qtbot):
     assert fc.outputValues()['dataOut']['vals']['axes'] == ['y', 'z', 'x']
 
     # finally, specify manually. omitting inner shape doesn't work
+    # but will be caught by validation (and no data returned)
     node.grid = GridOption.specifyShape, dict(shape=(5, 2, 5))
-    assert fc.outputValues()['dataOut'].data_vals('vals').shape == (5,2,5)
-    assert not num.arrays_equal(
-        fc.outputValues()['dataOut'].data_vals('vals'),
-        vv.transpose((1,2,0)),
-    )
+    assert fc.outputValues()['dataOut'] is None
 
     # but using the right inner axis order should do it
     node.grid = GridOption.specifyShape, dict(order=['x', 'y', 'z'],