VPN router SRX5308 VPN license

We currently are using the SRX5308 VPN router on one school site and is planning to set up a VPN connection to a new school site which we plan to purchase and use the BR500. We located a VPN Client Lite for 5 Users disk which we have never used and quite sure it came with the SRX5308 . We installed the VPN software but it would not activate with "Activation error 70: Internal error. Please try the activation later." Any suggestion how this could be resolved? Thanks!