Can not edit Variants

-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.3.6 Stable
-- PHP version -- : 5.5.21
-- Browser(s) name and version -- : Current FireFox
-- Error-message(debug-mod must be tuned on) -- : An error has occurred.

I am unable to edit variants.

Hello,
Did you use a Super admin account to be sure that you have the correct access to your variants ?
If yes, can you :
- Activate the Joomla debug mode ("Administration->Global configuration->System->Debug System/Language")
- Set the "error reporting" option of the Joomla configuration to "maximum"
- Test it again so that you can see if it display an error message which will help you to understand from what your issue is coming.
Thanks.