All my messages are failing with "unknown error occured"

I have been using dialogflow for the past 2 months, and suddenly I notice that all my messages are returning with an error.

When I test it in dialogflow, it shows this cryptic error. We have not received any message about downtime and we got reports of this error from 9-Nov (5 days ago). No idea since when this has actually been broken and nobody reported it.

What should I be doing here ? There doesn’t seem to be any records of this error or any notification about it.