/errors/smart_campaign_error.proto 

--- v24/errors/smart_campaign_error.proto   2026-09-23 01:11:56.000000000 +0000
+++ v25/errors/smart_campaign_error.proto   2026-09-23 01:12:00.000000000 +0000
@@ -61,5 +61,17 @@

     // New Smart campaigns cannot be created.
     CREATION_FAILED = 9;
+
+    // The validate_only generate PMax feature is not supported yet.
+    VALIDATE_ONLY_GENERATE_PMAX_NOT_SUPPORTED = 10;
+
+    // The GBP enabled generate PMax feature is not supported yet.
+    GBP_ENABLED_GENERATE_PMAX_NOT_SUPPORTED = 11;
+
+    // The image enabled generate PMax feature is not supported yet.
+    IMAGE_ENABLED_GENERATE_PMAX_NOT_SUPPORTED = 12;
+
+    // The Smart Campaign to PMax conversion failed validation.
+    GENERATE_PMAX_CONVERTERS_FAIL = 13;
   }
 }