I've a clean installation of MediaWiki 1.35.0 on Ubuntu 20.04. I've also tried the new version 1.35.1 (installed via patch), but I do not get the CategoryTree displayed in the sidebar. I followed the instruction from the following wiki page: Extension:CategoryTree#Using CategoryTree in the Sidebar
This are the new lines in the LocalSettings.php:
$wgCategoryTreeSidebarRoot = 'Category:forest';
$wgCategoryTreeForceHeaders = true;
If I open the page, I get the error Category not found, but the category exists. I've uploaded some screenshots and the configuration file LocalSettings.php here: https://www.dropbox.com/sh/w2bg2gxmf9th6vl/AACcJEkKeERNBCNedPJJ47CRa
Does anyone have any idea what the problem could be?
If anyone has a working configuration with the latest version, that would help me a lot too.
Thank you very much.