[solved] Backend product add page broken

-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.4.1
-- PHP version -- : 5.3.10

Hi,

Since the update to Hikashop business 2.5.0 the backend product page is broken on my site, it's displaying only one column, styles are broken, buttons to add images are not displayed etc (you can check the attached screen-shot).

I seen that I can use the old style while adding &legacy=1 to the product editing page URL and it works to edit existing products.
But this is not working when adding new products.
Then I have to first add few infos for a new product using the broken page, save it, and edit the product adding &legacy=1 to the url.
It's not a critical problem but if you could tell me how to fix it it would be great while it's enough annoying.

Thanks.

Sincerely.

Bruno.

Ok, I just seen the widget to choose categories in the product editing page is broken also, even un legacy mode, and it's not possible for me to add categories for a product.
I need to use the new broken page to give a category to the product while the widget is broken un legacy mode.

Thanks Nicolas.
I switched from custom to default CSS and it works fine, every problem is fixed.

Sincerely.

Bruno.

I think I have the same problem, but can't find/get to the spot to switch the CSS setting. Attached is a screenshot. I thought I would find the CSS setting under "Advanced Settings", but if I click on any of the hyperlinks, the URL changes, but the page doesn't change. How can I get to to the place to switch the CSS setting to default?