I too am getting this error. I’ve only just installed this plugin so can’t say if this was due to a recent update or anything.
I’ve done some quick diagnosis. I can still upload images successfully which are below the resize limit I set with the plugin. However, when I try to upload an image larger I experience similar symptoms to @sepruda. The ajax uploader fails only returning the message ‘HTTP Error
‘. Using the browser uploader fails silently. Inspecting the request shows it was a 500 error but it too was silent. After enabling ‘WP_DEBUG
‘ the server spat out this with the 500 response:
Fatal error: Call to undefined function imagecreatefromjpeg() in /var/www/html/studio/wp-content/plugins/resize-image-after-upload/class.resize.php on line 183
I have ImageMagick installed on my server but not GD:
imagick module enabled
imagick module version 3.1.2
WordPress is able to resize images itself, however, via the Edit Image page.