Post installation

I recently upgraded to Drupal 10.2.7 and am encountering issues switching to CKEditor 5. After following the steps provided here, I tried to change my text editor to CKEditor 5 and hit save, but nothing happened. Instead of saving the change, I'm simply returned to the list of text formats and editors, and the text editor remains unchanged.

I have a project that allows a subscriber to post job requests for repair professional using a content type (Job Request). I would like the repair pro to be able to view the job request, and submit/edit an estimate. Ideally, there would be a way for both users to agree on the estimate and the subscriber can mark the estimate as accepted. Once the estimate is accepted, I would like the subscriber to be redirected to pay the estimate amount to the website account (not the repair pro). In which the pro will be paid once the work is completed.

Hello,
I'm writing to you because I have a very annoying problem.
This morning I made a few changes to my site, and then cleared the cache. To make sure everything was working, I went to my site's home page but got the following error message: “The website encountered an unexpected error. Please try again later.”
I went back into the settings and changed the site redirection from “mysite.com/node” to “mysite.com”.
I logged out...
Now I can't log in at all. I can no longer access the mysite.com/admin/login page.
Can you please help me?

In the core themes twig files are ordered in a hierarchy of directories.

In my sub theme I don't want that hierarchy at all, I just want to copy-paste any twig file that I need to customize --- directly to the sub theme directory and edit it each such file on spot, without navigating in directories or using softlinks.

Can I cancel the twig hierarchy in my sub theme?

I want to try to edit a global twig file, something more global or "one layer up" than even page.html.twig.

Is there a global twig file and if not can I create one and put it in the root directory of my website's sub theme?

After updating to Drupal 10.2.7, the "Add Field" button has disappeared.

Previously, I could navigate to Administration > Structure > Content Types > Type and add a new field or reuse an existing field. Despite having both Fields API and Fields UI installed and enabled, the button is no longer visible.

I've also tried changing the administration theme to both Gin and Claro, but the issue persists.