I just purchased Multiimage Upload for VM. It installed and enabled ok. But, when i try to upload multiple images, I get the following error:

vmError: Couldnt create thumb, file not found /home/abc123/public_html/images/stories/virtuemart/product/DSCN334368.jpg
vmError: Couldnt create thumb, file not found /home/abc12/public_html/images/stories/virtuemart/product/DSCN338843.jpg

It appears that the plugin is not creating the product thumbnails.

I am using Joomla 3.6.5 and VM 3.0.18

Please advise.