You are using the FREE version, which is limited in terms of orders per day and month.
Here are the order limitations at the slave side with our Free Plan:
max orders per Day: 20
max orders per Month: 50
To be able to continue to copy trades, you would need to subscribe to one of our plans.
Choose a plan and subscribe here: https://www.trade-copier.com/pricing/subscription
Select your Slave and assign the new subscription to your Slave.