Warning: Trying to access array offset on null in drupal_cms_installer_theme_registry_alter() on Drupal core 11.1.1 installation

Can you give me a few more details? Like what version of Drupal CMS is this (RC2? 1.x-dev?) Giving me the exact steps to reproduce, starting from zero, would also be useful...

Here are the steps :

1. I have downloaded drupal cms from here https://new.drupal.org/drupal-cms/release-candidate
2. I extracted zip at my local and run the command : /launch-drupal-cms.sh
3. After submit email and password I was facing this issue : https://www.drupal.org/project/drupal_cms/issues/3497786 🐛 Installer is broken in RC2 since release of 11.1.1 Active
4. to get working setup I Run this command : rm -rf web/profiles/drupal_cms_installer/cache works fine like mentioned in #3 by @siramsay ( https://www.drupal.org/project/drupal_cms/issues/3497786#comment-15929054 🐛 Installer is broken in RC2 since release of 11.1.1 Active )
5. Then I can able to complete installation but just after completion I was faced this issue

Thanks @manpreet_singh, that's super helpful! I'll see if I can reproduce it locally.

No reports of this since the launch of 1.0 so maybe obsolete?

Tentatively closing, but let's reopen it if this gets reported again.