SSL Site To Site VPNs between SG and XG
When you want to migrate customers from an SG to an XG Firewall one of the hardest issues come when you can't establish SSL site to site VPNs between SG (Astaro) and XG when the SG is the master.
Why can't the EPC files be compatible?
Why not just upgrade the SG to XG firmware? SG is based on older version of OpenVPN so there is probably something in the XG epc file that only works in the version on XG. If I had to guess I would say it is the encryption settings.