Apllication Data disappeared

SOS SOS
Is there anybody who can help me.
I had register a Device in TTN and i was getting Data from my device sensor(waspmote from Libelium) then suddenly the data in my console in The Things Network is empty and all previous data has disppeard.
How can i retrieve the data?

you can’t.

you have to take care off your data storage, the console only shows data as long as the browser is open.

TTN is not a datastore. Use MQTT to subscribe to your data feed and then put the data in your own database.