Unable to extract the content of pdf file in php - php

Question

Currently working on validating the pdf file. I have used PHP pdfparser in Laravel to extract the file. But some files are unable to extract. I come up with the solution to downgrade the pdf file to resolve the issue but still not working for me.
I tried to downgrade the pdf file from version 1.7 to 1.4 but it's not allowing me to do so.
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use Smalot\PdfParser\Parser;
use Xthiago\PDFVersionConverter\Guesser\RegexGuesser;
use Symfony\Component\Filesystem\Filesystem;
use Xthiago\PDFVersionConverter\Converter\GhostscriptConverterCommand;
use Xthiago\PDFVersionConverter\Converter\GhostscriptConverter;
class ApiController extends Controller {
public function varifyDocument(Request $request, Parser $parser) {
$request = $request->file();
$file = $request['file'];
//Get the version of the pdf file.
$guesser = new RegexGuesser();
$version = $guesser->guess($file);
//If pdf version is 1.7 then convert it to 1.4.
if($version == "1.7") {
$command = new GhostscriptConverterCommand();
$filesystem = new Filesystem();
$converter = new GhostscriptConverter($command, $filesystem);
$converter->convert($file, '1.4');
}
$pdf = $parser->parseFile($file);
$pages = $pdf->getPages();
foreach ($pages as $page) {
echo $page->getText();
}
}
}
I need to read the content of the pdf file and identify it has any vulnerability or not.