One Way Issue with VPN

We have a VPN tunnel set up between two locations. Location A can access location B with no problems. However, when trying to go from location B into location A, I can only reach the firewall. 

I followed the cookbook procedures to set up the tunnel. http://cookbook.fortinet.com/site-to-site-ipsec-vpn-two-fortigates/ 

I have also verified that all IP's, policies, and static routes match on both firewalls. Both locations are on different networks. The firewall in location A is a fortigate 60E firmware v 5.4.1 and location B has a fortigate 60D firmware v 5.2.5.

Any ideas on what the issue might be here?