Black screen after login 18.04

Question

After login into my main account, I get a black screen that lasts up to an hour after which the desktop will usually load and works like normal.

zany130@andres-X470-AORUS-ULTRA-GAMING
    OS: Ubuntu 18.04 bionic
    Kernel: x86_64 Linux 5.0.17-050017-generic
    Uptime: 12m
    Packages: 4523
    Shell: bash 4.4.19
    Resolution: 2560x1080
    DE: GNOME 
    WM: GNOME Shell
    WM Theme: Arc-Dark
    GTK Theme: Arc-Dark [GTK2/3]
    Icon Theme: Paper
    Font: Roboto 11
    CPU: AMD Ryzen 7 2700X Eight-Core @ 
    16x 3.7GHz [53.5°C]
    GPU: GeForce GTX 1080
    RAM: 8407MiB / 16048MiB    

Update 1: Hello it's been a while so I'll give an update. My Ubuntu install is still crashing. For a time it got worse where 90% of the time my main account won't load. I created a second test account and that loads perfectly fine with no delay whereas the main could take hours(seriously I would go play ps4 while I waited)gotten better by removing some extensions as now its 50/50 whether I can sign in. Also a few things of note, my HDD indicator keeps blinking throughout the whole process. I have checked the disk for errors and it came back fine. I will try it again, though as maybe all the forced reboot did something. Sometimes it crashes before logging into an account but this is rare.so maybe on top of my having something messed up there's something also messing up the login globally. I haven't been able to pinpoint exactly what extensions, if it is an extension, crashes my account I have gone one by one enabling the extensions and deleting the seemingly responsible extensions and it will work for a few reboots and then start again IDK why but it seems like the act of disabling or enabling a extensions fixes the problem for the next boot. Sorry, this turned into such a long thing with so many ]posts I just wanted to document all I have tried to do and noticed. I'm at a loss as to what to do other than just using another account or disabling all the extensions before logging out or rebooting and then enabling them after I login. Idk if the last one would work

Update2: After trying Prateek kkY it worked for all of yesterday I tried several reboot and shutdowns and it was fine so I turned it off and today I went to use it and it wouldn't log in to my account again

Update3: I'm attaching my logs form a boot that took an hour on the black screen.

https://drive.google.com/file/d/1OTiP2RxJOG3d3Yuh-OPzhRZPv2s6sklu/view?usp=sharing

Answer 1

Make sure no late startup jobs and auto-start applications are loading, sometimes Ubuntu get stuck in while starting some network and gtk applications (dhcpcd, netctl and systemctl) make sure NVIDIA latest or its drivers are loaded normally, do blacklist Nouveau drivers, also do some simple sanity checks. steps to override start/stop jobs:

1. Open system.conf

   $ sudo gedit /etc/systemd/system.conf
   

2. Change lines

   #DefaultTimeoutStartSec=90s
   #DefaultTimeoutStopSec=90s
   

   remove the pound symbol and change both 90s to 5s, after edit

   DefaultTimeoutStartSec=5s DefaultTimeoutStopSec=5s
   

3. finally do

   $ sudo systemctl daemon-reload
   

   and reboot.

Answer 2

black screen or mouse/touchpad freeze problem after login is resolved with the following actions in addition to the system.conf file edit.

1. mask the NetworkManager-wait-online service => https://askubuntu.com/a/1166492/1761962

2. display hidden Startup Apps, then uncheck unnecessary startup apps => https://help.ubuntu.com/community/ShowHiddenStartupApplications

3. reconfigure gdm3 => https://askubuntu.com/a/1260286

---

It needs additional commands for the unnecessary startup apps like below.

systemctl mask org.gnome.SettingsDaemon.Smartcard.service --user
systemctl mask org.gnome.SettingsDaemon.Wacom.service --user
systemctl mask org.gnome.SettingsDaemon.Wwan --user
systemctl mask org.gnome.SettingsDaemon.UsbProtection --user