Additionnal product images in admin.

[-Tony-]

Hi
Joomla 3.4.5
virtuemart 3.0.12

I've a problem with the product images in admin i did not have before.
For the first image upload it's okay.
But for the others images (additionnal) i can't modify the name of the unique folder (can't remove "_product" at the end as before) and i can't add the url off thumbnail used as before.
So i can't create new product for the moment :p

It is as if it does not want to change the data in the tables.

I've read some topic about images problem in this section but i've not find answer to my question.
Thank's for your help.

[Geppux]

About the add of _product I make in this way:
I upload the first image with his name and his alt description, when I load another image, seen that the image name must be unique and this is why the program add  _product, before uploading the image, I insert a different name then the new image will have another name.
I hop I was clear in my explanation, bye.
Giuseppe