cannot add or change images using + button

-- HikaShop version -- : 2.6.1 30 march 2016
-- Joomla version -- : 3.4.8
-- PHP version -- : 5.6.19
-- Browser(s) name and version -- : Chrome 49.0.2623.87 (64-bit)
-- Error-message(debug-mod must be tuned on) -- : no error message to be seen except for forbidden access on favicon.

While editing a product in Hikashop backend I want to add or change an image.
Using the + button I expect to open a modal to choose an image.
This function does not work. And no error to be seen.
When I press the + button to add a file I do get a modal.

See attached animated gif

Hi,

It this issue still present even with another popup mode ?
You have maybe a problem with the already present images in the gallery, a corrupted file or a PHP error when trying to load the content. If you set the error reporting level to "maximum" do you see any error ?

update from Joomla 3.4.8 to Joomla 3.5.0 seems to be solving the issue