diff --git a/src/bonsai/bonsai/tool/blender.py b/src/bonsai/bonsai/tool/blender.py
index aa9656c76e..e5f7824836 100644
--- a/src/bonsai/bonsai/tool/blender.py
+++ b/src/bonsai/bonsai/tool/blender.py
@@ -1915,7 +1915,17 @@ class Blender(bonsai.core.tool.Blender):
     @classmethod
     def get_addon_preferences(cls) -> bonsai.bim.ui.BIM_ADDON_preferences:
         blender_package_name = cls.get_blender_addon_package_name()
-        return bpy.context.preferences.addons[blender_package_name].preferences
+        addon = bpy.context.preferences.addons.get(blender_package_name)
+        if addon is None:
+            raise RuntimeError(
+                f"Bonsai's addon preferences could not be found: Bonsai registered itself as "
+                f"'{blender_package_name}', but that is not a currently enabled Blender addon. "
+                "This usually means the Bonsai install is broken or in an inconsistent state, for "
+                "example if it was moved to a different extension repository without restarting "
+                "Blender. Please restart Blender, or reinstall the Bonsai extension from "
+                "Preferences > Get Extensions."
+            )
+        return addon.preferences
 
     @classmethod
     def get_addon(cls, name: str) -> Union[types.ModuleType, None]:
diff --git a/src/bonsai/test/tool/test_blender.py b/src/bonsai/test/tool/test_blender.py
index 5f6aa72430..31c8f0ea67 100644
--- a/src/bonsai/test/tool/test_blender.py
+++ b/src/bonsai/test/tool/test_blender.py
@@ -237,3 +237,20 @@ class TestGetObjectFromGuidMissing(NewFile):
         bpy.ops.bim.create_project()
         assert tool.Ifc.get() is not None
         assert subject.get_object_from_guid("3iyt7r$Hf4_hQYNhBIDJI4") is None
+
+
+class TestGetAddonPreferences(NewFile):
+    """``get_addon_preferences`` looks up Bonsai's own cached registration name in
+    ``bpy.context.preferences.addons``. If Bonsai's install ends up in an
+    inconsistent state (e.g. moved to a different extension repository without
+    restarting Blender), that cached name stops matching any enabled addon. This
+    must fail with an actionable ``RuntimeError``, not the bare ``KeyError`` a raw
+    dict-style lookup would raise."""
+
+    def test_returns_preferences_for_the_currently_registered_addon(self):
+        assert subject.get_addon_preferences() is not None
+
+    def test_raises_actionable_error_when_registered_name_is_stale(self, monkeypatch):
+        monkeypatch.setattr(bonsai, "REGISTERED_BBIM_PACKAGE", "bl_ext.some_other_repo.bonsai")
+        with pytest.raises(RuntimeError, match="bl_ext.some_other_repo.bonsai"):
+            subject.get_addon_preferences()