I'm running into this problem also. My thumbnails don't generate on their own. I have to upload them manually. I just upgraded from PHP 7.2 to 7.3 and now I'm receiving this error. I can still add photos to the product, but it doesn't generate a thumbnail.
QuoteWarning: Use of undefined constant IMG_GIF - assumed 'IMG_GIF' (this will throw an Error in a future version of PHP) in /home/luxefi5/public_html/administrator/components/com_virtuemart/helpers/mediahandler.php on line 437
Warning: Use of undefined constant IMG_JPG - assumed 'IMG_JPG' (this will throw an Error in a future version of PHP) in /home/luxefi5/public_html/administrator/components/com_virtuemart/helpers/mediahandler.php on line 438
Warning: Use of undefined constant IMG_PNG - assumed 'IMG_PNG' (this will throw an Error in a future version of PHP) in /home/luxefi5/public_html/administrator/components/com_virtuemart/helpers/mediahandler.php on line 439
Warning: Use of undefined constant IMG_WBMP - assumed 'IMG_WBMP' (this will throw an Error in a future version of PHP) in /home/luxefi5/public_html/administrator/components/com_virtuemart/helpers/mediahandler.php on line 440
Versions?
I have been running my sites on php7.3 for months
This is the only issue I've had with PHP 7.3. Other than this my site runs great.
You forgot version VM, sure :)
is the gd library enabled?
I believe it still uses it.
Usually you have to configure each php version on server
VirtueMart 3.8.8
I just got with my host and they enabled the GD library. The errors are gone but the thumbnails still don't generate on their own.
after enable you try vm tools for creating thumbs for existing images - tools you can use after setup in configuration
dynamic thumbs turned on?
they are generated when you view the frontend