Hello @tco
First , please use the markdown when posting Codes/Logs/Configuration files shown here
Second, your macros are incorrect in this section of the Notification file.
It should be like this.
Source: ${message.source}
Heure: ${message.timestamp}
if you have other fields that are needed and are NOT default fields, you need to set them like this example:
Users: ${messages.fields.users}