diff --git a/backend/mpc-system/services/service-party-app/electron/modules/grpc-client.ts b/backend/mpc-system/services/service-party-app/electron/modules/grpc-client.ts
index cbf80b79..3c622f54 100644
--- a/backend/mpc-system/services/service-party-app/electron/modules/grpc-client.ts
+++ b/backend/mpc-system/services/service-party-app/electron/modules/grpc-client.ts
@@ -550,6 +550,10 @@ export class GrpcClient extends EventEmitter {
       throw new Error('Not connected');
     }
 
+    if (!this.connected) {
+      throw new Error('gRPC client not connected');
+    }
+
     // 保存订阅状态（用于重连后恢复）
     this.activeMessageSubscription = { sessionId, partyId };
 
@@ -560,15 +564,22 @@ export class GrpcClient extends EventEmitter {
       try {
         oldStream.cancel();
       } catch (e) {
-        // 忽略
+        console.log('[gRPC] Ignored error while canceling old message stream:', (e as Error).message);
       }
+      this.messageStream = null;
     }
 
-    this.messageStream = (this.client as grpc.Client & { subscribeMessages: (req: unknown) => grpc.ClientReadableStream<MPCMessage> })
-      .subscribeMessages({
-        session_id: sessionId,
-        party_id: partyId,
-      });
+    try {
+      this.messageStream = (this.client as grpc.Client & { subscribeMessages: (req: unknown) => grpc.ClientReadableStream<MPCMessage> })
+        .subscribeMessages({
+          session_id: sessionId,
+          party_id: partyId,
+        });
+    } catch (e) {
+      console.error('[gRPC] Failed to create message stream:', (e as Error).message);
+      this.activeMessageSubscription = null;
+      throw e;
+    }
 
     // 保存当前流的引用，用于在事件处理器中检查是否是当前活跃的流
     const currentStream = this.messageStream;