Drupal 8.x

I'm having a strange error enabling uc_attribute.

Drupal v 8.9.2, Ubercart 8.x-4.0-alpha5

drush pm:enable uc_attribute gives this error:

Hello everyone! I'm very new to drupal world and my partners ask me to update and renew their old drupal 6 website; at the moment a friend helped me updating drupal version from 6 to 8. This is the website: www.iisbeitalia.org. The main things about the old website were 3 pages where a list of users was showed - example: page 1 = list of registered users experts in subject A, page 2 = list of registered users experts in subject B, page 3 = list of C subject experts...

I'm frustrated. I just want to create a module which simply checks if the current content being opened has been created by currently logged in user else deny it.

We can do using form_alter.

But I'm not able to find full source code(including *.yml files).

All examples(including example module in Drupal) show path in routing.xml. I don't need a path actually.

Where is the full source code example just for this?

Having just installed a "fresh" test D9.0.2 system using the suggested composer-based template, I am now in the middle of defining users (only got 4), content types, responsive image styles, etc. 

I now would like to have a look at "automagically" migrating my D8.9.2-content nodes to D9.0.2. My site isn't big, but it is in 3 languages (German, English and Italian), maybe some 150 pages. Is there any "proved" tool to migrate those nodes? Thanks for any hints.

Regards 
H. Stoellinger

I've been using Drupal since 2007 and loved it!! have done more than 200 websites.

However, lately I am kind-of stranded and probably will be moving to WordPress soon since Drupal is becoming more and more geeky and command-based.

It's the 21st century guys!! and you have to have respect for non-geeks like me. I'm old enough to know DOS but now I can't go back to command line interfaces. I am spoiled, as are many other web designers nowadays.

I created a new Content type called Announcements. I want the Announcement nodes to have a specific background color.
Is that possible without going into coding level? is there a module that can change background colors? my search didn't come-up with any results.

Am using the ST Octoban theme.