SendEachForMulticastAsync

Can any one please let me know the reason why this comes "At least one message is required" ?
while calling await FirebaseMessaging.DefaultInstance.SendEachForMulticastAsync(message);

There is valid payload, but still at times , does not know why this is occurring

If any one can share more details, please do share...

Error sending SendEachForMulticastAsync message: At least one message is required

Start by reproducing the FirebaseMessaging.DefaultInstance.SendEachForMulticastAsync(message) call with the reported payload and inspect the message object immediately before invocation. The issue does not name a file or test; done would require a confirmed reproduction and a documented cause or a clearly scoped fix for the intermittent “At least one message is required” error.

Written by the indexing model from the issue text.