scripts/startup/bl_ui/properties_data_mesh.py

@@ -124,7 +124,7 @@ class MESH_UL_shape_keys(UIList):
             row = split.row(align=True)
             row.emboss = 'NONE_OR_STATUS'
             if key_block.mute or (obj.mode == 'EDIT' and not (obj.use_shape_key_edit_mode and obj.type == 'MESH')):
-                row.active = False
+                split.active = False
             if not item.id_data.use_relative:
                 row.prop(key_block, "frame", text="")
             elif index > 0: