How to remove the + sign for image upload

-- HikaShop version -- : 2.4.0
-- HikaMarket version -- : 1.6.2
-- Joomla version -- : 3.4.1
-- PHP version -- : 5.5.12
-- Browser(s) name and version -- : Chrome 43

Hello,

I'm sure that it's a local problem with my template (the vendor didn't find a solution so far), but when i click on the + sign to add a new image in Vendors/Dashboard/Product/Add new, the page is overlapped by a div layer without any value displayed. I have to refresh the page and press the upload button in order to be able to upload a image.

Using another template, i found that a popup is displayed but still i don't see any text or form elements available for use.
Because i can't wait for my theme designer to find a solution to this, i need to disable the + sign and keep only the upload button for images and files (yes, the same problem within the files area).

I tried to add display:none; for class hikam_add_btn in media/com_hikamarket/css/frondend_default.css; the button is hidden but still clickable.

Thank you