Stop the service and reset the data
sudo systemctl stop fiammad
cp $HOME/.fiamma/data/priv_validator_state.json $HOME/.fiamma/priv_validator_state.json.backup
rm -rf $HOME/.fiamma/data
curl -L http://snapshots.liveraven.net/snapshots/testnet/fiamma/fiamma-testnet-1_latest.tar.lz4 | tar -Ilz4 -xf - -C $HOME/.fiamma
mv $HOME/.fiamma/priv_validator_state.json.backup $HOME/.fiamma/data/priv_validator_state.json
Restart the service and check the log
sudo systemctl start fiammad && sudo journalctl -u fiammad -fn 100 -o cat