Restore Backup of CRM environment

Hi,

I have a CRM 2013 production environment installed on a server. I created a new organisation of CRM on 31st March on the same server by taking the backup of prod database.The new organisation got created and worked fine. I wanted to refresh this organisation with the latest data of production on a monthly basis. Hence I restored the prod database of 30th Apr onto the new organisation database. The database got restored but while logging onto new organisation of CRM I received the error of system id not present. How could this happen since the prod database is the same??How can I refresh the new CRM on a monthly basis with the prod CRM??

Thanks in advance