While sending Push Notification Delivery, we are seeing the below error in our instance for iOS deliveries.
From a search on developer forums it looks to be an error due to iOS Registration Token, but is there a way to know more about what the issue is?
The Error text is : Invalid hex character: S\ Error 'Invalid hex character: S' while generating frame to send
You need to check with app development team. In some of the cases I have seen that issue was the conversion of FCM to APNS key.
However app development team would be right team to help you out on this.
Looks like GMC/FCM is enabled only for Android and not IOS. Please refer to the below documentation for more information .