Synaptic not launching on Ubuntu 17.10

[Hasimir]

I just installed Ubuntu 17.10
Everything seems to be working quite ok, except that I'm unable to use Synaptic.
I installed it with (apparently) no problems, but when I click its icon, nothing happens.
Trying from the terminal this is the error I get:

No protocol specified
Unable to init server: Could not connect: Connection refused
(synaptic:3572): Gtk-WARNING **: cannot open display: :0

Any idea what this means?

Thanks in advance for the support

[1fallen]

This has been disused a few times now here.
Enter this in the terminal:

xhost +si:localuser:root

This will give synaptic a temporary permission for this session only.
This thread would be a better fit in Ubuntu Development Version.
Reached Release.

[Hasimir]

I searched but I failed to find this info. Sorry for the redundant post. And thanks a lot for the quick reply and help

[1fallen]

No Worries.
And your welcome.

[Cavsfan]

Is this solved because as of today Monday August 21, 2017 Synaptic does open without doing anything extra.

I just tried it and it opens after updates and a reboot.

[amano]

Hmm. Maybe you are on X without noticing?

I didn't see any Synaptic related changes the last days/week.

[dino99]

https://bugs.launchpad.net/ubuntu/+s...c/+bug/1712089

[P-I H]

After upgrade I had to reboot to get the new functionality
The login alternatives have changed to
- Ubuntu
- Ubuntu on Xorg

I made login to Ubuntu and checked if the applications I'm mostly use still work. I checked
- Synaptic
- Kodi in snap version
- Steam with CIV IV
- Handbrake
- Chromium
- Gmail
- Gedit
- Tweaks
- Software
All worked fine
However there seems to be a problem with logout and login

[harry332]

After updating my setup the same issue with synaptic here too.
I use only gnome-session and the gnome wayland session was automatically chosen.
Well, I changed the session to gnome on Xorg.
Now synaptic works again without any command line tricks after every boot.

This is the update I am talking about:
gdm3 (3.25.90.1-0ubuntu2) artful; urgency=medium * debian/patches/ubuntu_prefer_x11_session.patch:
- remove x11 session preference now that both Ubuntu and GNOME
switched to wayland

[Cavsfan]

Yes, you are correct I managed to get a Gnome Classic session installed and it would seem it would be Wayland but, it was in an X11 session.
I have these options when logging in:

1. Gnome
2. Gnome Classic
3. Gnome on Xorg
4. Ubuntu
5. Ubuntu on Xorg

The first is definitely Wayland and 2 and 3 are Xorg. Option 4 is Wayland and 5 is as it states Xorg.

Synaptic did not open on any Wayland sessions I tried.

Guess I forgot Synaptic opens normally on an Xorg session.