Why can't I add a URL to the "Category Media URL"

[PostHistorie.nl]

I run VirtueMart 3.0.18.7 Blue Corvus 9410 on J 3.6.5 I have ~10.000 items in my shop.

The images are all stored on my remote image server and this works fine, when adding a product I point to there.

However I now seem to have the problem that Vmart keeps complaining about  missing images because it's looking for them in an non-existent place:

Error
vmError: File not found /var/www/bla.com/http://www.mysite.com/images/bla-2015/TC-2015-009/Img9717.JPG


I can not change the "Product Media URL" to be a URL or a domain... (it says  so in the mouse hover over: URL to the images of the products (relative to joomla root, do not add http or domain)).

Also I can not sync my media to vmart because this will kill my server:


[Wed Jan 04 13:46:09 2017] [error] [client x.x.x.x] PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 72 bytes) in /var/www/bla.com/administrator/components/com_virtuemart/helpers/vmtable.php on line 148, referer: http://bla.com/administrator/index.php?option=com_virtuemart&view=media


I dont really mind so far and I can supress the error warnings, however my com_virtuemart.log.php log is filling up like crazy, every click it does a media search.

So what do you advise to do?