I get this as well trying to create a Google account from System Settings -> Online Accounts. Dialog title for me is 'Unable to finish -- System Settings' though, not Plasma. Latest Kubuntu 17.04 with all updates.
This is also reported over on KDE bugtracking: https://bugs.kde.org/show_bug.cgi?id=379270. ** Bug watch added: KDE Bug Tracking System #379270 https://bugs.kde.org/show_bug.cgi?id=379270 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1070873 Title: kde-telepathy, impossible to connect to gmail accounts To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/meta-kde-telepathy/+bug/1070873/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs