Steps to replicate the issue (include links if applicable):

• Installation of 1.43.1 MediaWiki from official install, with VisualEditor, Bootstrap, MultimediaViewer

What happens?:

• I get this error.

• Similar errors with Less_Exception_Compiler appear while using page edit (Visual editor is not working, same with WikiEditor when enabled).
• Page looks like the CSS is broken,
  
  (this is with Vector-2022 skin enabled) many functionalities does not work. When using default skin as chameleon (installation via composer) the page looks fine, but "edit" button does not work, only "edit source code", but still, no VisualEditor or WikiEditor present.
  

• Also, the images are not rendering in correct places and with specified options (eg.: this is a [[Plik:Logo.png|thumb|right|200px| Logo Zorzowej Krainy]])
  

What should have happened instead?:

Page should be able to load in Vector, extensions should be working, basically Less_Exception_Compiler error should not be here. I spent too much time trying to troubleshoot this and i can see that there are some (i believe) codex variables ommited from mediawiki.skins.variables.less file, but i don't know what do do with this (I am really new to the Wiki community). also, Vector appear to not properly import this .less file. Problem also appears when using other pre-installed MediaWiki skins. I tried to manually enter missing variables and i managed to get Vector to display the buttons, but as there are no codex variables that was the maximum i could do (and it was very daunting to manually enter every variable for the whole skin)

Software version
MediaWiki 1.43.1
PHP 8.4.0
Chameleon 5.0.1
Vector 1.0.0
WikiEditor 0.5.4
VusialEditor REL1_43