Not a bug error css after update to php 7.4

[canina]

Affected version

2.0

I upgraded to php7.4 and suddenly there is a CSS error throughout the site
I looked at the network tab and I see that there are 2 reads to the css.php file

In the second reading it returns a valid css file but in the first reading it returns the content below

<?php

$dir = DIR;
require ($dir . '/src/XF.php');

XF::start($dir);
$app = XF::setupApp('XF\Pub\App', [
'preLoad' => ['masterStyleModifiedDate', 'smilieSprites']
]);

$request = $app->request();
$input = $request->filter([
'css' => 'str',
's' => 'uint',
'l' => 'uint',
'k' => 'str'
]);

$cssWriter = $app->cssWriter();

$showDebugOutput = (\XF::$debugMode && $request->get('_debug'));

if (!$showDebugOutput && $cssWriter->canSend304($request))
{
$cssWriter->get304Response()->send($request);
}
else
{
$css = $input['css'] ? explode(',', $input['css']) : [];
$response = $cssWriter->run($css, $input['s'], $input['l'], $input['k']);
if ($showDebugOutput)
{
$response->contentType('text/html', 'utf-8');
$response->body($app->debugger()->getDebugPageHtml($app));
}
$response->send($request);
}

 

[Chris D]

XenForo 2.0 is not compatible with PHP 7.4 and XenForo 2.0 is no longer supported.

You will either need to downgrade PHP or upgrade XenForo to the latest 2.1 release.