Hi there,

Could you share the replication steps for this issue? Is the issue when you click on a push notification and then the app opens?

Also, does it happen in Android, iOS, or both?

Best regards,

Alexandre

Hi @Tamilarasan Senthilkumar ,

I suspect this happens when OneSignal triggers a callback after the screen that owns that client action is no longer active. 

In your case: 

• User taps a push notification 
• OutSystems navigates to a screen 
• Meanwhile, OneSignal still fires a callback (Opened / Value / Data) 
• That callback tries to invoke MainFlow.Home.OnValueCallback But Home is not active anymore 

From OutSystems documentation and forum threads: 

• OneSignal callbacks are asynchronous 
• They may fire: 
  • Before navigation finishes 
  • After navigation destroys the previous screen 
• If the callback is wired to: 
  • A Screen Client Action 
  • A Block Client Action 

And that screen/block is destroyed, this results in invalid call. This is not OneSignal‑specific, but OneSignal makes it easy to hit because of delayed events.

Solution:

Move notification handling to a Global Client Action. OneSignal callbacks must not call Screen client actions directly.

• Create a Global Client Action, for example: HandlePushNotification 
• Bind OneSignal events to this global action: 
  • OnNotificationOpened 
  • OnNotificationReceived 
• Inside the global action: 
  • Parse notification payload 
  • Store navigation intent in a Global Variable 
  • Trigger navigation safely 

This aligns with the OutSystems platform guidance.

Hope this helps.

Cheers,

Saugat