PDf embed error

I've just downloaded and enable the Embed PDF plugin and was trying out the various settings for different viewers. It worked for a while but now I get the following error and I don't know what it means. "Notice: Undefined property: stdClass::$id in C:\wamp64\www\beemeadow\plugins\content\pdf_embed\pdf_embed.php on line 91" See image.

Have tried to reinstall, but no luck. Please help.