Having used the most excellent Hurricane Electric for the longest time I decided to relocate. In so doing I realised that I was moving from a PHP 5.2 to a PHP 7.1 environment. Gulp! Has it been that long. Expecting lots o' issues, but amazingly no. Just the tiniest of tiny issues:

PHP Warning:  preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead in /var/www/wp-content/plugins/codecolorer/codecolorer-core.php on line 50

So, comment out:

  function BeforeHighlightCodeBlock($content) {
    $content = preg_replace('#(\s*)\[cc([^\s\]_]*(?:_[^\s\]]*)?)([^\]]*)\](.*?)\[/cc\2\](\s*)#sie', '$this->PerformHighlightCodeBlock(\'\\4\', \'\\3\', $content, \'\\2\', \'\\1\', \'\\5\');', $content);
    $content = preg_replace('#(\s*)\(.*?)\(\s*)#sie', '$this->PerformHighlightCodeBlock(\'\\3\', \'\\2\', $content, \'\', \'\\1\', \'\\4\');', $content);
    return $content;
  }

adding

  function BeforeHighlightCodeBlock($content) {
    $content = preg_replace_callback('#(\s*)\[cc([^\s\]_]*(?:_[^\s\]]*)?)([^\]]*)\](.*?)\[/cc\2\](\s*)#si', function($matches){
      return $this->PerformHighlightCodeBlock($matches[4], $matches[3], $matches[2], $matches[1], $matches[5]);
    }, $content);
    $content = preg_replace_callback('#(\s*)\(.*?)\(\s*)#si', function($matches){
      return $this->PerformHighlightCodeBlock($matches[3], $matches[2], '', $matches[1], $matches[4]);
    }, $content);
    return $content;
  }
php