Trying to access array offset on value of type null

The errors may show up on the site currently showing the errors, as I'm assuming something somewhere along the line became corrupt. Does your current site have content you've added or settings you don't want to lose?

If not, then starting fresh is definitely your best bet here. If you install a site from the Library and want to use a different one instead, be sure to remove the site you installed first for the best experience: https://docs.generatepress.com/article/removing-imported-site/

Let me know :)

The site with the fresh WP instalation is my current site, so everything is working fine. I have also tried to import other sites as before (Info, Avery, Geek) and again no errors. I hope it is solved now.

I am going to start filling the Scribe site. If there will be any problem, I will let you know.

Thank you and your whole team for fantastic support!

No problem! Glad it's working now :)