diff --git a/src/nodeClass.js b/src/nodeClass.js
index c7e730a..8e919a9 100644
--- a/src/nodeClass.js
+++ b/src/nodeClass.js
@@ -167,39 +167,42 @@ class nodeClass {
     this.node.on(
       "input",
       async (msg, send, done) => {
-            const vg = this.source;
-            const RED = this.RED;
+        const vg = this.source;
+        const RED = this.RED;
+        try {
           switch (msg.topic) {
-            case "registerChild":
-                //console.log(`Registering child in mgc: ${msg.payload}`);
+            case "registerChild": {
               const childId = msg.payload;
               const childObj = RED.nodes.getNode(childId);
-              vg.childRegistrationUtils.registerChild(
-                childObj.source,
-                msg.positionVsParent
-              );
+              if (!childObj || !childObj.source) {
+                vg.logger.warn(`registerChild skipped: missing child/source for id=${childId}`);
+                break;
+              }
+              vg.childRegistrationUtils.registerChild(childObj.source, msg.positionVsParent);
               break;
-
+            }
             case 'setMode':
               vg.setMode(msg.payload);
               break;
-            case 'execSequence':
+            case 'execSequence': {
               const { source: seqSource, action: seqAction, parameter } = msg.payload;
               vg.handleInput(seqSource, seqAction, parameter);
               break;
-
-            case 'totalFlowChange':  // een van valves is van stand veranderd waardoor total flow is veranderd
+            }
+            case 'totalFlowChange': {
               const { source: tfcSource, action: tfcAction, q} = msg.payload;
-              vg.handleInput(tfcSource, tfcAction, Number(q)); 
+              vg.handleInput(tfcSource, tfcAction, Number(q));
               break;
-
+            }
             default:
-              // Handle unknown topics if needed
               vg.logger.warn(`Unknown topic: ${msg.topic}`);
               break;
           }
-          done();
+        } catch (error) {
+          vg.logger.error(`Input handler failure: ${error.message}`);
         }
+        if (typeof done === 'function') done();
+      }
     );
   }
 
@@ -210,7 +213,7 @@ class nodeClass {
     this.node.on("close", (done) => {
       clearInterval(this._tickInterval);
       clearInterval(this._statusInterval);
-      done();
+      if (typeof done === 'function') done();
     });
   }
 }