I suspect that you are not doing something wrong.
net30 topology is structurally built into the ovpnmain.cgi code. You can’t just change the topology by statements in the conf file. The error says that it is looking for an Address pair (10.0.1.2/10.0.1.1) which is the net30 topology I believe but if you have changed the topology it will not find those.
It would be good if just changing the conf files was sufficient as the net30 topology has been deprecated and so ovpnmain.cgi needs to be modified to deal with that but it is not easy as any change needs to migrate people from net30 topology without breaking any of their existing connections. The change mustn’t require people to recreate all of their OpenVPN connections. It also has to be applied to both Road Warrior and Net to Net approaches as well.
That change is definitely beyond my capabilities.