Restore config 60f

Hello I have 2 FGT 60F. I am trying to restore from one to the other. They are both same firmware 6.4.8. One is completely configured and registered with policies, addresses, VLANs, security profiles, etc. Backup was taken from fully config 60f. The other 60f has matching firmware and otherwise not configured. When trying to restore from backup, system says it is taking too long and fails. Need to factory reset to get back on the device. 

Any help is appreciated. Thanks. 
#Fortigate