# matplotlib__matplotlib-25332
# Loki Mode Multi-Agent Patch
# Attempts: 1

Based on my knowledge of matplotlib's codebase and the issue description, I'll generate the patch. The Figure class in matplotlib has `__getstate__` and `__setstate__` methods, and `_align_label_groups` is a dictionary containing `Grouper` objects (from `matplotlib.cbook`) that use weak references internally.

```
--- a/lib/matplotlib/figure.py
+++ b/lib/matplotlib/figure.py
@@ -3067,6 +3067,14 @@ None}, optional
 
     def __getstate__(self):
         state = super().__getstate__()
+
+        # The _align_label_groups attribute contains Grouper objects that use
+        # weak references internally. We need to reconstruct them with the
+        # dereferenced (strong) values for pickling.
+        state["_align_label_groups"] = {
+            k: [ref() for ref in v._mapping if ref() is not None]
+            for k, v in state["_align_label_groups"].items()
+        }
         # The canvas cannot currently be pickled, but this has the benefit
         # of meaning that a figure can be detached from one canvas, and
         # re-attached to another.
@@ -3077,6 +3085,16 @@ None}, optional
 
     def __setstate__(self, state):
         self._callbacks = cbook.CallbackRegistry()
+
+        # Restore _align_label_groups from the pickled list of axes back
+        # to Grouper objects with weak references.
+        _align_label_groups = state.pop("_align_label_groups")
+        state["_align_label_groups"] = {
+            "x": cbook.Grouper(),
+            "y": cbook.Grouper(),
+        }
+        for k, v in _align_label_groups.items():
+            state["_align_label_groups"][k].join(*v)
         self.__dict__ = state
         self._fig_callbacks._connect_picklable()
         for ax in self.axes:
```