Companion of paritytech/polkadot#7098

runtime/common/src/xcm_configs.rs

@@ -32,7 +32,10 @@ use xcm_executor::{
 // substrate
 use frame_support::{
 	log,
-	traits::{tokens::currency::Currency as CurrencyT, ConstU128, OnUnbalanced as OnUnbalancedT},
+	traits::{
+		tokens::currency::Currency as CurrencyT, ConstU128, OnUnbalanced as OnUnbalancedT,
+		ProcessMessageError,
+	},
 	weights::{Weight, WeightToFee as WeightToFeeT},
 };
 use sp_core::Get;
@@ -86,7 +89,7 @@ impl ShouldExecute for DenyReserveTransferToRelayChain {
 		message: &mut [Instruction<RuntimeCall>],
 		_max_weight: Weight,
 		_weight_credit: &mut Weight,
-	) -> Result<(), ()> {
+	) -> Result<(), ProcessMessageError> {
 		if message.iter().any(|inst| {
 			matches!(
 				inst,
@@ -100,7 +103,7 @@ impl ShouldExecute for DenyReserveTransferToRelayChain {
 					}
 			)
 		}) {
-			return Err(()); // Deny
+			return Err(ProcessMessageError::Unsupported); // Deny
 		}
 
 		// An unexpected reserve transfer has arrived from the Relay Chain. Generally, `IsReserve`