Some users reported they are not receiving notifications, I believe it's related to "ErrCode 3 - DeviceSubscriptionExpired" since I find out this in the logs (DeviceToken omitted):
ERROR SDAPI.Notifications - SetResult - ErrCode 3 - DeviceSubscriptionExpired - APA91******
What action my program need to take when get this error?
I'm already updating the DeviceToken using NotificationsRegistrationHandler.
Gx 15 U2 C#
The best way to have Push Notifications up and running with GeneXus, is using GeneXus OneSignal implementation. We recommend to use OneSignal GeneXus implementation instead of 'SDAPi.Notifications'
Take a look here