PDF Thumbnails stopped working in v5.9

[dsawyers]

We've been able to verify on our server using a staging site that when version 4.8.3 is running, PDFs upload and generate a thumbnail. When the same staging site is updated to v5.9 with no other changes made to server, PHP version, plugins, etc, the thumbnails stopped generating. We've also used a staging site with V5.9 to apply a core theme and turn off all plugins that the thumbnails don't generate. Every test we've run comes down to WP Core update breaking the functionality.

[antpb]

Thanks for reporting this. I am moving this into the 6.1 milestone so we can investigate what changed.

[antpb]

Hello @dsawyers ! I was doing some testing with this ticket and am seeing now that WordPress 6.1 is generating PDF thumbnails as expected. It

If your server supports Imagick you should see the expected image thumbnail output.

You can check under Tools->Site Health->Info to see what image engine your WordPress uses. I am going to close this as worksforme (though it was probably valid at one time!) Please feel free to reopen this ticket if this issue persists. Thank you!