New version 1.8.9 – Issue

Hello,
First thanks for your plugin

After upgrade to 1.8.9
This option not working anymore
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Use default thumbnail: checked on me
If checked, when no thumbnail is found, show a default one from the URL below. If not checked and no thumbnail is found, no image will be shown.
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Default thumbnail: path to the image
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Instead showing error:
Fatal error: Call to undefined function tptn_get_first_image() in /home/account/public_html/wp-content/plugins/contextual-related-posts/contextual-related-posts.php on line 691

not other part of the page is loaded it`s breaks everything

Any suggests?
Thanks

https://www.ads-software.com/plugins/contextual-related-posts/