Wordpress - No Thumbnails Generated

I figured it out!

In my php.ini file I had to uncomment extension=php_gd2.dll, then it started working after I rebuilt the images I uploaded :)

Thanks,
Josh

I solved the issue as well.

With reference to Josh Rodgers' answer, I had to log into my server's CPANEL, under "Software and Services", depending on how your server is set up, there is "Select PHP Version", then tick the "gd" box, save, and refresh your wordpress post or media page, then retry the upload.

If you are looking at your wordpress via FTP, you can refresh your uploads folder and see that the various sizes have appeared, i.e. imagename100x100.jpg, etc, etc.

I hope this helps someone.

Bernard

I was having the same problem on my new server install with Ubuntu 16.04 and PHP 5.6. The problem is that Wordpress relies on the PHP GD module in order to generate the thumbnails. The insight from Josh led me to install the GD module using this command via SSH:

sudo apt install php5.6-gd

And then restarting apache:

sudo service apache2 restart

Worked like a charm!