Facebook messenger error

I have a new Facebook messenger error. Does anyone know what this means? My configuration was working fine, nothing changed.

2017-12-05 15:17:11 ERROR (SyncWorker_3) [homeassistant.components.notify.facebook] Error 400 : (#1200) Temporary send message failure. Please try again later. (Code 1200)

The FB-Messenger seems to be down at the moment. It’s HA-independent…

Thanks for the information