/errors/asset_group_signal_error.proto

--- v23/errors/asset_group_signal_error.proto   2026-06-18 21:38:48.000000000 +0000
+++ v24/errors/asset_group_signal_error.proto   2026-06-18 21:38:54.000000000 +0000
@@ -50,5 +50,9 @@
     // asset group referenced by the audience being used in the asset group
     // signal.
     AUDIENCE_WITH_WRONG_ASSET_GROUP_ID = 4;
+
+    // The asset group signal cannot be removed because it is the last one in
+    // the Local Services Ads PMax asset group.
+    CANNOT_REMOVE_ALL_SIGNALS = 5;
   }
 }