Maybe a bit late, but who knows… 
I have 12.3 running on my VM-server (13.2 on my work-station).
First, the upgrade caused my configuration for the remote system to disappear, which I find odd.
Yes, happened to me too. The new virt-manager (1.0.1, old was 0.9.5) stores its configuration a bit differently (new: ~/.config/dconf/user vs. old: ~/.config/gconf/apps/virt-manager/).
Second, after the upgrade to 13.2, virt-manager can no longer connect to the VM server. It dies with the “useful” message:
Error polling connection ‘qemu+ssh://ingham@clarke.i-pi.com/system’: An error occurred, but the cause is unknown
I have no problem with virt-manager or virsh connecting remotely.
The error message is from a command executed via the ssh-tunnel which virt-manager set up. The text “requires an argument” (from one of your other posts) appears in /usr/share/virt-manager/virtManager/console.py on line 261
Maybe there is something in virt-manager’s logs (~/.cache/virt-manager/virt-manager.log).
Also see libvirtd’s logs on the VM-server if you have access (probably /var/log/messages).
There are logging options in /etc/libvirt/libvirtd.conf (on the VM-server; backup before you change!)
I am using ssh public key authentication, and the agent has my key, so I can ssh to the server without having to enter a password. Once on the server, I can start virt-manager as me and work with VMs. This means that it should not be a permission problem.
You might want to try this:
virsh --connect=qemu+ssh://ingham@clarke.i-pi.com/system list
If you get an error with this command: virsh has a --debug option, see man virsh.
List of my installed packages on the VM-server with 12.3:
# rpm -qa | egrep -i 'kvm|qemu|virt' | sort
kvm-1.3.1-3.6.2.x86_64
libvirt-1.0.2-1.22.1.x86_64
libvirt-client-1.0.2-1.22.1.x86_64
libvirt-python-1.0.2-1.22.1.x86_64
python-virtinst-0.600.3-2.2.1.x86_64
qemu-1.3.1-3.8.1.x86_64
qemu-linux-user-1.3.1-3.8.1.x86_64
qemu-tools-1.3.1-3.8.1.x86_64
virt-utils-1.1.9-6.1.1.x86_64
List of my installed packages on my work-station with 13.2:
# rpm -qa | egrep -i 'kvm|qemu|virt' | sort
libvirt-client-1.2.9-1.3.x86_64
libvirt-glib-1_0-0-0.1.9-2.1.4.x86_64
libvirt-login-shell-1.2.9-1.3.x86_64
libvirt-python-1.2.9-1.2.x86_64
qemu-block-curl-2.1.0-2.9.x86_64
qemu-linux-user-2.1.0-2.9.x86_64
qemu-tools-2.1.0-2.9.x86_64
typelib-1_0-LibvirtGLib-1_0-0.1.9-2.1.4.x86_64
virt-install-1.0.1-14.7.1.noarch
virt-manager-1.0.1-14.7.1.noarch
virt-manager-common-1.0.1-14.7.1.noarch
virt-viewer-1.0-2.1.4.x86_64
You do not have qemu-linux-user and libvirt-login-shell, but after reading their rpm-descriptions I doubt if installing them would be the solution. Not having virt-install is probably not an issue.
You probably do not need this, but, in case somebody is wondering, my permissions:
--- /etc/libvirt/libvirtd.conf.orig 2013-03-20 17:03:53.055466005 +0100
+++ /etc/libvirt/libvirtd.conf 2014-10-06 11:26:57.000000000 +0200
@@ -81 +81 @@
-#unix_sock_group = "libvirt"
+unix_sock_group = "libvirt"
@@ -98 +98 @@
-#unix_sock_rw_perms = "0770"
+unix_sock_rw_perms = "0770"
@@ -129 +129 @@
-#auth_unix_ro = "none"
+auth_unix_ro = "polkit"
@@ -138 +138 @@
-#auth_unix_rw = "none"
+auth_unix_rw = "none"
(This is a diff-file which can be fed to patch (backup first)).
The ssh-user is a member of the libvirt group (ingham in this post).
Kind regards,
Leen