Probleme mit altem PHP Script und DB Anbindung

Fatal error: Uncaught Error: Call to undefined function get_magic_quotes_runtime() in C:\xampp\htdocs\ts12\fpdf\fpdf.php:1043 Stack trace: #0 C:\xampp\htdocs\ts12\fpdf\fpdf.php(77): FPDF->_dochecks() #1 C:\xampp\htdocs\ts12\stafftopdf.php(39): FPDF->__construct() #2 {main} thrown in C:\xampp\htdocs\ts12\fpdf\fpdf.php on line 1043

<?php
require('fpdf/fpdf.php');  
    
    include('classes/Core.php');  

        $id_staff=null;
        $date=null;
        //echo $_GET['id_customer']; 
        if(isset($_GET['id_staff']) && is_numeric($_GET['id_staff'])){  
           $id_staff=abs($_GET['id_staff']);  
        }
        if(is_null($id_staff) || $id_staff == ""){  
            echo "Leider konnte die Anfrage nicht bearbeitet werden.";  
            exit;
        }
        
        if(isset($_GET['date'])){  
           $date=$_GET['date'];  
           $date = date("Y-m-d", strtotime(urldecode($date)));  
        }
        
        
        
        $newLocale = setlocale(LC_TIME, 'de_DE', 'de_DE.UTF-8');  
        
        //echo $id_customer;
        Core::connectDB();
        if(isset($date)){
            $treatment_dates = Core::getTreatmentDate($date, $id_staff);
        }
        else{
            $treatment_dates = Core::getTreatmentDatesByStaff($id_staff);
        }
        $staff = Core::getStaff($id_staff);
        
  //      echo var_dump($treatment_dates);
//        echo var_dump($staff);
//        exit;
        $pdf = new FPDF();
        $pdf->AddPage();
        
        
        $id_company= "";  

        $pdf->SetTextColor(57,57,57);
        $pdf->SetFont('helvetica', '', 20);  
        $pdf->Cell(0,20, utf8_decode('Terminübersicht'));  
        $pdf->Ln(20);
        
        $pdf->SetTextColor(57,57,57);
        $pdf->SetFont('helvetica','',11);  
        $PosXSurname= $pdf->GetX();
        $PosYSurname=$pdf->GetY();
        
        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode('Nachname: ')),0 ) ;  
        $pdf->SetTextColor(12,12,12);
        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode($staff['surname'])),0 ) ;  
        $pdf->Ln();
        $pdf->SetTextColor(57,57,57);
        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode('Vorname: ')),0 ) ;  
        $pdf->SetTextColor(12,12,12);
        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode($staff['prename'])),0 ) ;  
        
        
//        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode('Nachname: ')),0 ) ; 
//        $pdf->SetTextColor(12,12,12);
//        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode($staff['surname'])),0 ) ; 
//        $pdf->Ln();
//        $pdf->SetTextColor(57,57,57);
//        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode('Vorname: ')),0 ) ; 
//        $pdf->SetTextColor(12,12,12);
//        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode($staff['prename'])),0 ) ; 
//        $pdf->Ln();
//        $pdf->SetTextColor(57,57,57);
//        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode('Geburtstag: ')),0 ) ; 
//        $pdf->SetTextColor(12,12,12);
//        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode($customer['birthday'])),0 ) ; 
//        $pdf->Ln();
//        $pdf->SetTextColor(57,57,57);
//        $pdf->Cell( 50,6,  html_entity_decode(utf8_decode('Straße: ')),0 ) ; 
//        $pdf->SetTextColor(12,12,12);
//        $pdf->Cell( 50,6, utf8_decode($customer['street']),0 ) ; 
//        $pdf->Ln();
//        $pdf->SetTextColor(57,57,57);
//        $pdf->Cell(50,6, 'Ort: ', 0); 
//        $pdf->SetTextColor(12,12,12);
//        $pdf->Cell(55,6, utf8_decode($customer['zipcode']). " " . utf8_decode($customer['town'])); 
//        $pdf->SetTextColor(57,57,57);

        $pdf->Ln(20);
        
        
        $pdf->Cell(10, 6, "", 'B',0);  
        $pdf->Cell(30, 6, "Wochentag", 'B');  
        $pdf->Cell(30, 6, "Datum", 'B');  
        $pdf->Cell(15, 6, "Beginn", 'B');  
        $pdf->Cell(15, 6, "Ende", 'B');  
        $pdf->Cell(30, 6, "Behandlung", 'B');  
        $pdf->Cell(60, 6, "Patient", 'B');  
        
        $pdf->Ln();
        $count = 1;
        foreach($treatment_dates as $td){
//            $d = DateTime::createFromFormat('d.m.Y H:i', $td['treatment_date']); 
            $d = strtotime($td['treatment_date']);//date('d.m.Y H:i', strtotime($td['treatment_date']));  
            $now = strtotime('now');//date("Y-m-d H:i:s");  
            if($d > $now || $date){
//            $interval = $now->diff($d);
            
            $pdf->SetTextColor(57,57,57);
            $pdf->Cell(10,6, $count++. ".)",0);  
            $pdf->SetTextColor(12,12,12);
            $td_date = split(' ', $td['treatment_date']);  
            
            $day = strftime('%A', strtotime($td['treatment_date']));  
            $pdf->Cell(30,6, $day);
            $pdf->Cell(30,6, $td_date);
            $pdf->Cell(15,6, $td_date[1]);
            
            $pdf->Cell(15,6, $td['treatment_time_end']);  
            $treatment_name = Core::getTreatment($td['id_treatment']);  
            $pdf->Cell(30, 6, $treatment_name['shortcut']);  
//            $staff = Core::getStaff($td['id_staff']); 
//            $pdf->Cell(30,6, $staff['surname']); 
//            $pdf->Cell(20,6, $d);
            $patient = Core::getPatient($td['id_patient']);  
            $pdf->Cell(60, 6, html_entity_decode(utf8_decode($patient['surname'])).', '.html_entity_decode(utf8_decode($patient['prename'])));  
            $pdf->Ln();
            }
        }
        Core::closeDB();
        $pdf->Output();
        
        exit;

        


?>

	switch($dest)
	{
		case 'I':  
			// Send to standard output
			$this->_checkoutput();
			if(PHP_SAPI!='cli')  
			{
				// We send to a browser
				header('Content-Type: application/pdf');  
				header('Content-Disposition: inline; filename="'.$name.'"');  
				header('Cache-Control: private, max-age=0, must-revalidate');  
				header('Pragma: public');  
			}
			echo $this->buffer;
			break;
		case 'D':  
			// Download file
			$this->_checkoutput();
			header('Content-Type: application/x-download');  
			header('Content-Disposition: attachment; filename="'.$name.'"');  
			header('Cache-Control: private, max-age=0, must-revalidate');  
			header('Pragma: public');  
			echo $this->buffer;
			break;
		case 'F':  
			// Save to local file
			$f = fopen($name,'wb');  
			if(!$f)
				$this->Error('Unable to create output file: '.$name);  
			fwrite($f,$this->buffer,strlen($this->buffer));
			fclose($f);
			break;
		case 'S':  
			// Return as a string
			return $this->buffer;
		default:
			$this->Error('Incorrect output destination: '.$dest);  
	}
	return '';  
}