Removed startup apps, not cannot login to Unity desktop

[steeldriver]

did startx work? if not, what error messages did it produce?

[cigtoxdoc]

Thank you for your help.

startx gave the following messages
Fatal server error:
Server is already active for display 0
If server is no longer running, remove /tmp/.XO-lock
ddxSigGiveUp: Closing log
Invalid MIT-MAGIC-COOKIE-1 keyInvalid MIT-MAGIC-COOKIE-1 keyxinit:giving up
xinit: unable to connect to X server: Resource temporarily unavailable
xinit: server error

[steeldriver]

and you did stop lightdm first, right? did it really stop? what does

ps -ef | grep X

say?

[grahammechanical]

there should be an easier way to recover from this error.

Why? Why should there be an easy way of doing anything? There are many ways we can break an OS. They are all undocumented. Therefore, the methods for fixing things are also undocumented. An easy answer is to re-install Ubuntu. We are all guessing here. Try this

Use Ctrl+Alt+T to open a terminal and run the command

software-center

That should load the Ubuntu Software Centre. Search for ubuntu-desktop. Is it still installed? If not install it and shutdown and reboot. You may have removed ubuntu-desktop. Regards.

[cigtoxdoc]

root 2022 1359 0 08:40 tty7 00:00:01 /usr/binX :0 -auth /var/run/lightdm/root:0 -nolisten tcp vt7 -novswitch
john 2441 2331 0 08:47 tty1 00:00:000 grep --color=auto X

BTW, when I did shut down lightdm and run startx, I got a blank screen

Thank you for your help

[cortman]

Apparently that lighdm process didn't get killed properly- it's the first line returned. Kill it with

sudo kill -9 process_id

What you posted says the process ID is 2022. It's probably changed now, but that's the field you want for the PID.
Then follow steeldriver's instructions.
Good luck.

[cigtoxdoc]

killed process as instructed
startx
screen goes black for a few minutes
then get No protocol specified (multiple times)
then get

xinit: giving up
xinit: unable to connect to X server: Resource temporarily unavailable

waiting for X server to shut down ddxSigGiveUp: Closing log
Server terminated successfully (0). Closing log file

xinit: server error
xauth: error on locking authority file /home/john/.Xauthority

[steeldriver]

OK can you check the ownership + permissions on your home dir and ICE / X authority files please? e.g.

ls -ld ~
ls -l ~/.{ICE,X}authority

Since this appears to affect guest logins it's probably worth checking your available disk space as well

df -h

[cigtoxdoc]

df -h gave for /dev/sda2 size = 145G, used 96G, avalable 41G Use 71%
udev/dev 1%
tmpfs/run 1%
/run/lock 1%
/run/shm 1%

ls -l ~/.{ICE,X}authority = -rw------- 1 john john 31140 Mar 1 08:53 /home/john/.ICEauthority
= -rw------- 1 root root 0 Mar 5 08:40 /hone/john/.Xauthority

ls -ld ~ = drwxr-xr-x 82 john john 12288 Mar 5 09:39 /home/john

[steeldriver]

OK you need to fix the ownership of your .Xauthority file - either

sudo chown john:john ~/.Xauthority

or simply remove it and let the server create a new one next time (doesn't need sudo)

rm ~/.Xauthority

Then either try startx again or jump right to restarting lightdm if you're feeling lucky

sudo service lightdm start