Error sending Push-Notification to Android devices via REST API

Hi,

we use the SCP-Service „Development and Operations“ to send Push-Notifications via REST API. Everything worked fine, we were able to send notifications to iOs and Android devices, but today Android Push-Notifications stopped working with the following warning:

„Cannot hand-off a notification to GCM due a wrong configuration in the application com.sap.fiori.client. Please check the GCMs Sender ID and API_KEY configuration for the application {0}“

Is there any possible way to update the GCM API_KEY or is this caused by an expired licence?

I am grateful for every suggestion …

Best regards

Tim