Comment 92 for bug 360818

I seems like this problem is already fixed upstream:

http://bugs.kde.org/show_bug.cgi?id=213900#c3

I gave it a try and recompiled plasma-widget-networkmanagement after applying this patch. This seems to fix the "No VPN secrets!" issue.

Here is what I did in detail:

apt-get source plasma-widget-networkmanagement
sudo apt-get build-dep plasma-widget-networkmanagement
cd plasma-widget-networkmanagement-0.9-svn1029786+ag1/
dpkg-buildpackage -rfakeroot -b
sudo dpkg -i ../plasma-widget-networkmanagement-0.9-svn1029786+ag1-0ubuntu1_amd64.deb

The bug is located in the code that saves the data from the widget. That's why you need to delete the config entries for all your openvpn connections and recreate them again after installing the fixed package!