I have get the extension working for Mediawiki 1.37 by replacing line no 160 of extensions/PDFEmbed/PDFEmbed.hooks.php from
$pdfFile =wfFindFile($filename);
to
$pdfFile = MediaWikiServices::getInstance()->getRepoGroup()->findFile($filename);
I have get the extension working for Mediawiki 1.37 by replacing line no 160 of extensions/PDFEmbed/PDFEmbed.hooks.php from
$pdfFile =wfFindFile($filename);
to
$pdfFile = MediaWikiServices::getInstance()->getRepoGroup()->findFile($filename);
I think,
$pdfFile = MediaWiki\MediaWikiServices::getInstance()->getRepoGroup()->findFile($filename);
is the right solution. It works on my MediaWiki.
Greetings
Meinolf