I am currently using WSO2 EMM 2.0.1, and platform configuration I use GCM, I have follow the step in document, and already set the API key and Sender ID. in the device I manage to get the GCM reg id too, but when I perform operation on EMM, at the console and log, I have receive this error (Exception occurred while sending the GCM notification : null). I have try to find the solution through online, but I cant find any solution to solve this problem.
Here is a screenshot for the error:
Please advice and help, Thanks.