Stuck on welcome screen when attached an external display with laptop

[Mazamal Ehsan]

I faced this issue on Ubuntu 20.04. My system is fully updated, no update is pending.

Steps to reproduce

1) Attach an external display with a laptop
2) Set external display as primary
3) Select only single display option
4) Restart your laptop while external display is attached

When the first ubuntu screen is displayed after restart, before login screen. The system stops there, ubuntu logo with round circle animation works, but system does not proceed to login screen. I have waited for about 15 minutes but it did not proceed to login screen, instead it showed round circle animation with ubuntu logo. Then I forcefully turned off my laptop by holding down power button. The I detached my external display and it worked fine. I have faced this issue many times.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1888416/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Sebastien Bacher (seb128)]

Thank you for your bug report, the screen configuration change only apply to the user session and shouldn't impact the login screen. Is your monitor on? Are you sure the password entry isn't displayed on it? if you move the mouse can you bring it to the laptop screen? what happens if you just type enter, your password and then enter again?

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1872159, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.