The desktop environment has disappeared

[deb-ian]

Hello!

As I've written in the title I'm running into the following problem: my desktop environment disappeared some hours ago.
I installed Debian 9.6.0 this morning on my laptop. At the moment I have Windows 10 in my main SSD and a partition of my HDD with Debian "9.6.0". The whole OS was running just fine this morning but after some restarts at one point when I click on Debian in the bootloader it doesen't start with my actual desktop environment, that is Cinnamon, and it only launches the bash interface. My main user and the root user have the same password that I've set during the installation process and even the domain of the system. So think that the system itself it's still integer but I don't know how it doesn't manage to load Cinnamon. Moreover if I remember correctly this problem happened after I've started Windows 10 for the first time after the installation, this could be related.

Help this newbie guys ahaha

[xepan]

Perhaps a problem with the display-manager
(that thing which usually is seen after boot, just like the tty you see now, a username and a password to login and run X ).

Been ages i ran a display-manager, and things have changed since systemd (which i don't use either).

A good start to troubleshoot the problem would be to log in and run "startx"
iirc back in the days you had to first "service stop lightdm/whatyouhave", but with systemd things have changed. Try a simple "startx" first of all, perhaps it will already give a hint what might be wrong.
If no one jumps in you might try:

Code: Select all

echo false >/etc/X11/default-display-manager" will also disable the DM, 

and reboot, then login and run "startx"


also something like:
dpkg -l | grep cinnamon
or: apt-cache policy cinnamon
or such. Probably superfluous, as you would have realized if it was removed.

~/.xsession-errors (~ = /home/username) or
/var/log/Xorg.0.log
might have hints too.

[deb-ian]

Perhaps a problem with the display-manager
(that thing which usually is seen after boot, just like the tty you see now, a username and a password to login and run X ).

Been ages i ran a display-manager, and things have changed since systemd (which i don't use either).

A good start to troubleshoot the problem would be to log in and run "startx"
iirc back in the days you had to first "service stop lightdm/whatyouhave", but with systemd things have changed. Try a simple "startx" first of all, perhaps it will already give a hint what might be wrong.
If no one jumps in you might try:

Code: Select all

echo false >/etc/X11/default-display-manager" will also disable the DM, 

and reboot, then login and run "startx"


also something like:
dpkg -l | grep cinnamon
or: apt-cache policy cinnamon
or such. Probably superfluous, as you would have realized if it was removed.

~/.xsession-errors (~ = /home/username) or
/var/log/Xorg.0.log
might have hints too.

Thank you!!
I'll try it lately I'll let you know with a post

[stevepusser]

You could also log in in the terminal interface and look at your apt history log

Code: Select all

cat /var/log/apt/history.log | more

(most recent changes at the end of the file)

to see if any recent updates or removals could be to blame.

[deb-ian]

Perhaps a problem with the display-manager
(that thing which usually is seen after boot, just like the tty you see now, a username and a password to login and run X ).

Been ages i ran a display-manager, and things have changed since systemd (which i don't use either).

A good start to troubleshoot the problem would be to log in and run "startx"
iirc back in the days you had to first "service stop lightdm/whatyouhave", but with systemd things have changed. Try a simple "startx" first of all, perhaps it will already give a hint what might be wrong.
If no one jumps in you might try:

Code: Select all

echo false >/etc/X11/default-display-manager" will also disable the DM, 

and reboot, then login and run "startx"


also something like:
dpkg -l | grep cinnamon
or: apt-cache policy cinnamon
or such. Probably superfluous, as you would have realized if it was removed.

~/.xsession-errors (~ = /home/username) or
/var/log/Xorg.0.log
might have hints too.

Thank you!
I've tried writing the command "startx" at the begging, but the OS tells me that it was waiting for an X server to begin accepting the connection. What is that? And about what server is it writing about?
Then I've entered the code that you've suggested me:

Code: Select all

echo false >/etc/X11/default-display-manager

Then I've rebooted the machine, launched startx and then Cinnamon showed up. But this until this morning! I've done the same process but now I can't access to the desktop environment anymore! Now I'm sure that is something related to the display manager, because when I load up the OS it tells me that it fails loading the Lighting Display Manager. I don't know what a Lighting Display Manager is, and a display manager, in general either. Can you help me to understand about what we are talking? Also I've tried to upload some photos taken from the CLI in order to understand the problem that I have, but I can't upload them into my reply! How can I do that?

[None1975]

For pictures use thumbnail links. Also, try

Code: Select all

dpkg-reconfigure lightdm

as root or sudo.

[xepan]

A display-manager is just a piece of software which helps you to log in and (usually) start a graphical environment.
lightdm is one display-manager, but there are several (gdm is another one, slim another one, ssdm too ).
Usually desktop-environments have a default display manager (say gnome uses gdm), but it is not a hard requisite.
The other option is to not use a display-manager, but boot to tty, log in, and, if wanted, start a graphical environment with the command startx.


I wouldn't worry too much about the details. It will come with time.
There might be some people who switch back and forth, but most pick one way to log in and stick to it. No need to know that much about other solutions. imho, of course.

[golinux]

We run across problems like this often in Devuan because of how the systemd/policykit stuff interacts with various WM. If you are using sysvinit rather than systemd that could possibly be the source of your issue. There could be a hard systemd dependency in there that is preventing X from launching. Just a guess. You can read how we deal with session management HERE.