The following information relates to installation of ThinLinc on an Ubuntu or Debian platform. The latest recommended version of this platform for use with ThinLinc can be found in the ThinLinc Administrator's guide, under "Server Requirements" .

Unity fails to start on Ubuntu 17.04

Unity sessions are expected to be started differently in the latest release of Ubuntu compared to previous releases. This causes this desktop environment to fail to start in ThinLinc. There is currently no known workaround to get Unity working.

You will have to use a different desktop environment, for example LXDE, XFCE, KDE or GNOME. For more information, see bug 6190.

Missing Python 2 and/or modules for installation

A default installation of Ubuntu no longer includes some Python 2 modules that are important when installing ThinLinc, and may even lack Python 2 itself. Make sure everything is installed on the system, before installing ThinLinc, using this command:

$ sudo apt install python python-gtk2 python-apt

Local printer (thinlocal)

bug in CUPS in Ubuntu forces all print jobs to be marked as raw data. This breaks ThinLinc's universal handling of local printers and results in PDF data being sent directly to the local printer. Many printers can natively handle PDF print jobs and should work despite this bug. There is unfortunately no known workaround for other printers though.

ThinLinc commands are not found

The PATH is not automatically extended with /opt/thinlinc/bin for normal users and /opt/thinlinc/sbin for root on Debian systems. For easy ThinLinc usage, you need to fix this using a system-wide configuration file.

Polkit authentication dialogs during login

Recent versions of Unity, GNOME and KDE contain bugs ([1],[2]) which causes Polkit authentication dialogs to appear during login, when resizing the session etc. It is possible to prevent such dialogs by creating the file /etc/polkit-1/localauthority/50-local.d/40-thinlinc-no-auth-dialogs.pkla with this content:

[Prevent auth dialogs in ThinLinc]
Identity=unix-user:*
Action=org.freedesktop.color-manager.create-device;org.freedesktop.color-manager.create-profile;org.freedesktop.color-manager.delete-device;org.freedesktop.color-manager.delete-profile;org.freedesktop.color-manager.modify-device;org.freedesktop.color-manager.modify-profile;org.debian.apt.update-cache
ResultAny=no
ResultInactive=no
ResultActive=yes

For more information, see Bug 5584.

Gnome screensaver crash

A bug in Gnome screensaver causes it to crash when logging in to ThinLinc. It is recommended to uninstall the package until the bug can be resolved:

$ sudo apt remove gnome-screensaver