Problem fatal in section of live site

https://espacoecologiconoar.com.br/acervo/
Section of site is down.
Files Yii are of 04/2016, I don’t know Yii.
This is part of live site that suddenly stopped working.
Site is in WordPress and Yii.
I don’t know this version of Yii
Where is the requirement checker report?

I don’t know exactly what your problem is (perhaps somebody else know already?)
I can think of some change in the hosting environment (or some other update)

Latest version of the framework here.
The requirement checker comes in a sibling directory to the framework directory.

If you want to try the latest version, rename the current framework directory (e.g .bak) and upload the latest framework dir. Should be enough for a basic site. Or perhaps upload the whole 1.1.22 package content to a new web accessible directory, and try it out there.

Ando This?:
https://espacoecologiconoar.com.br/acervo/

The question is: what was changed? If the Yii site wasn’t touched, perhaps a wp update.
May be autoloader related. I don’t think I can help you with this.

Some wiki articles about Yii/WP integration here

Just visited the page. Now some progress.
I think you can get rid of “Function get_magic_quotes_gpc() is deprecated” by adding ~E_NOTICE in the start script (index.php). I can’t say for sure this is a good idea in production, it probably is.

// Report all errors except E_NOTICE error_reporting(E_ALL & ~E_NOTICE);

It looks like you still use an older version of Yii 1.1.
There seems to be changes for compatibility with PHP 7.4
(I assume your hosting provider updated recently.)
The part of code in question looks like this in Yii 1.1.22

protected function normalizeRequest()
{
	// normalize request
	if(version_compare(PHP_VERSION,'7.4.0','<'))
	{
		if(function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc())
		{
			if(isset($_GET))
				$_GET=$this->stripSlashes($_GET);
			if(isset($_POST))
				$_POST=$this->stripSlashes($_POST);
			if(isset($_REQUEST))
				$_REQUEST=$this->stripSlashes($_REQUEST);
			if(isset($_COOKIE))
				$_COOKIE=$this->stripSlashes($_COOKIE);
		}
	}

while your page still looks like this

 protected function normalizeRequest()
 {
     // normalize request
     if(function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc())
     {
         if(isset($_GET))
             $_GET=$this->stripSlashes($_GET);
         if(isset($_POST))
             $_POST=$this->stripSlashes($_POST);
         if(isset($_REQUEST))
             $_REQUEST=$this->stripSlashes($_REQUEST);
         if(isset($_COOKIE))
             $_COOKIE=$this->stripSlashes($_COOKIE);
     }