Workaround for this:
After the failed upload, verify that the directory /var/ipfire/ovpn/n2nconf/YOURN2NPACKAGENAME exists, with a .conf file in it
Copy the cert in the package to /var/ipfire/ovpn/certs
Change owner/group of the cert to nobody/nobody
Then edit /var/ipfire/ovpn/ovpnconfig and add a new line, copying one already present and changing it is best. Do note that the lines are not in order: the first number is incremental, you must find the highest linenumber and add 1. Then modify the line with the correct values for your networks. Disable and enable the connection and you should be up.