After enabling the Language module and Configuration translation, the site fails on Clear Caches, update.php and possible elsewhere with a general error "The website encountered an unexpected error. Please try again later."

The Recent Log messages shows this on update.php:

After I have been looking for a solution for several weeks now and have not found it in various videos / tutorials, I would like to ask here. If there is already somewhere a solution / explanation a short hint or a link would be helpful. Thanks in advance.

I have built a multilingual site. The translation of the links, menus etc. was easy and well explained.
However, I can't find a solution on how to translate the links for books and taxonomies.

Hi friends,
I've added a language, but i would like to know if i can change the Language Code from pt-br to pt,

Language code

That's because i'm using another system to access to my view and get those nodes passing the language by url
?language=pt, but now its like ?language=pt-br, so i would like to change code name,

Could you please help me?

Regards
Mario

I am playing around for some hours with multilanguage now but i could not figure out why the language switcher block is just showing the url im currently on for BOTH languages.

I configured language per domain using localhost domains i also added to the hosts file and the apache vhost, so they work locally.

EN(com): dev.texturecase4.com

DE: dev.texturecase4.de

I translated the Websites name/title to see if the switch works. If i manually switch the urls it will show the EN/DE title.

I have a multilingual website. But a view always shows all languages. How can I make a view show only the current language of the web page. I tried it with the filter criteria. But I don't see a language field to choose from. Why not, do I have to set anything else? I tried it according to this tutorial:
https://redfinsolutions.com/blog/display-multilingual-drupal-8-views

Hello,
I look after a small international Drupal website (de,en,it). At present the site is at 8.9.12. I would like to upgrade to D9. Is it possible to use module pathauto_i18n in D9 already?
If not, is there an "official" way to automatically create aliases for the various languages?
Thanks for your help.
H. Stoellinger