i go to Template-styles - and overwrite productdetails.
im using fancybox.
now i see
undefined/components/com_virtuemart/assets/images/fancybox/fancy_close.png
pleze fix it
If you override the style, you have to do the rest of the work too. Either put the image(s) into the right folder, or adjust the path in your override.
If you ask someone to please fix it, there is a forum for commercial jobs, you will definitely get help there.