Please check if the peer container is still up. If the container has crashed, then it cannot be reached for endorsement. Also checking the logs for peer0.org1.example.com will help.
First, you have to run .byfn.sh -m down it will delete all old configuration of docker and container images,
now you can run .byfn.sh -m up, by using this command you can up your network in hyperledger.
You simply have to do ./byfn.sh up and it will work. No need to use -m flag but first try to do ./byfn.sh down so it cleans itself.
I hope this will help. Let me know if you face any further difficulties.