I am not sure if this is a problem because I use the plugin
hot-linked-image-cacher
and it will get remote images i link to in my post and store them on my site and the image names can be rather long.
such as
014ca79b76397e705683442d83c40a29.jpg
13dd31f09a75071b54efe83808bdfee3.jpg
d3ae14f6f9fe239c66802092aaa11439.jpg
then the Post Thumb generates thumbs based on this
thumb_f03db6455d77bde122b24becaafee6ce.jpg
others are like
thumb_312JRNSW2GL._SL160_.jpg
and
files i upload by ftp and embed with a url are like
thumb_cockroach-1.jpg
Anyway about 10 to 20% of the first images in my posts are not being thumbnailed. They do not show up and the file thumb_thumbnail.jpg is being used…
however I have my default set to thumb_default100x100.png
I do not use WordPress to store my images either they are grabbed and cached or i ftp them into a folder.
All first in post images are local to the server prior to the thumbnail being generated.
https://www.ads-software.com/extend/plugins/alakhnors-post-thumb/
]]>in your file
post-thumb-functions.php
on line 470 comment this line
// curl_setopt ($handle, CURLOPT_MUTE, TRUE);
CURLOPT_MUTE is no longer an option and needs to be commented out or it will throw back an error.
https://www.ads-software.com/extend/plugins/alakhnors-post-thumb/
]]>