Create frontend_custom.css in config screen. Always Forbidden 403 error

Hi,

It's not a problem of HikaShop. That's because your hosting has some security system which refuses all the requests with potentially harmful text. And when you save a file, that system detects the file as a false positive and refuse it.
You could check with the hosting support to deactivate that security system or change its configuration to not flags these modifications as potentially harmful.
Otherwise, these are all saved as file overrides. So you don't necessarily need to go through the interface to do them:
- for language overrides, you can go through the Joomla translation override interface:
www.joomla-monster.com/documentation/tem...in-joomla-3-template
- for view overrides, you can also do that through the Joomla interface when you edit the template:
docs.joomla.org/Special:MyLanguage/J3.2:...r#Creating_Overrides
- for CSS, you can either add your CSS modifications to your template CSS files via the template manager (which is what I would recommend), or do a copy of the files in media/com_hikashop/css/ to modify them via FTP and then select them in the HikaShop configuration.