Thanks - changing the port fixed that error. But the other problem I'm having is with the Export of the OPVN file for Server 1. I had manually configured this server on my RT-N66U, and re-imported those settings into my RT-AC88U. The were working, but I wanted to make some changes. After doing so, when I try to Export to the OPVN file, the end of the file looks like this:
</ca>
<cert>
paste client certificate data here
</cert>
<key>
paste client key data here
</key>
resolv-retry infinite
nobind
While the Server 2 export actually includes the client certificate data and the client key data. I've tried erasing everything in all the fields on Server 1 when following this link: Content modification of Keys & Certification. However, it doesn't change the missing info on the Export. If I could just reset that entire Server 1 configuration back to the defaults, I think this might work properly once it is reconfigured. There's something hanging around that is preventing it from working properly, and I can't find what it is. Right now, I have Server 1 and Server 2 configured identically, except for the Port (1194 for 1 and 1195 for 2), but the Export button only produces a usable OPVN file for Server 2.