So the error that pops up most of the time is "Error: Call to undefined function each() in /usr/share/pear/Text/Diff/Engine/native.php on line 195".

And this is what the manual on php.net says:

each

(PHP 4, PHP 5, PHP 7)

each — Return the current key and value pair from an array and advance the array cursor

Warning This function has been DEPRECATED as of PHP 7.2.0, and REMOVED as of PHP 8.0.0. Relying on this function is highly discouraged.