CSS file doest not open on "System->Conf->Display"

-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.4.4
-- Browser(s) name and version -- : Firefox/Chrome

Hello,
I would like to change some CSS settings but when using System->Configuration->Display->CSS->front/backend->edit, the window is empty.
I am using the jsn-glass-pro template.
Thanks for any help

Hello,

1. Can you give us more information about your issue through some screenshots for example ?

2. Also, can you test it with one of the default Joomla template to see if it correctly works ?

Thank you.

Hello, Thanks for your answer,

Here is what I get (attached).

I also tried templates beez3 and beez5 for frontend and halthor for backend with no difference.
However it works fine on test site with same configuration.

Hi,
I tried to download and install again but this does not help.
I cannot check if it works on your demo site as demo user does not have rights to access those settings.
But it works on my test site.
It seems that all files which open with the "pen icon" are locked (css, language, "override taxe zone" or "image" in shipping configuration).
However I can update php files.

Hello,
It seems like that issue only happen with the last Joomla 3.4.4 version, you'll find the solution through that thread ; www.hikashop.com/forum/install-update/87...to-3-4-4.html#214269

Hello,
Thank for the tip. The popup now opens but does not open the file and displays an error 404 instead of css.
Same problem to select an image for transport but with error 403

Hi,
Thanks a lot, it works.
Good job
Bye