Sending data messages means that Restream is trying to connect the platform and if that message stays for too long, that means we are having issues with it.
Here are a few things you can try to solve this issue:
Please make sure you have all the necessary permissions to stream to YouTube.
If you have multiple Gmail accounts, please choose the same as your active YouTube channel! Gmail account itself doesn't mean that you have a YouTube channel associated with it.
Please make sure streaming is enabled on your YouTube account. You can check it here.
Note: It takes 24 hours to activate your YouTube account for live streaming.
Try reconnecting channel