Multishop error 403

[gius3pp3]

Hi,

i have a shop (Prestashop 1.6.1.18) of softair products and i need to advertise my products on Facebook.

Unfortunately Facebook allows all my products except one category: guns and rifles. For this reason they suggested me to put guns and rifles in another domain.

Now i created the multishop and I followed this procedure:
1) From cPanel i added a new third level domain
2) In Prestashop backend general setting i activated the multishop option.
3) In "Advanced parameters" i added the new shop in the same group with the only products category that i need.
The url is the same of cPanel.

If i try to open the new link in the third level domain, i have the 403 error.
What did I do wrong? What i can do to see the new website with the category products that i need to remove from my main website?
Hope that someone can help me.
Thank you

[gius3pp3]

I solved the problem contacting my server provider.

They change my third domain in "parked domain".

After i regenerate the .htaccess and the second shop works fine.

Thanks a lot for the many answers to my help 

[El Patron]

make sure to create rewrites from old domain to new domain to keep cat/prod link juice.

[gius3pp3]

I try to move some categories from the first shop to the second, but i loose the sub categories.

I can't see them in the main menu of the front end and in Advanced parameters > Multistore.

I try to use the query of this topic:
https://www.prestashop.com/forums/topic/535668-lost-sub-categories-after-changing-name-in-multistore/
and i can see the sub category only in the first shop main menu.

And in the backend Advanced parameters > Multistore there are only the category that i selected for the first shop.

In Catalog > Category, with "All stores" selected on the top, i have reassigned the sub catery to the category of the second shop, and now i can see the sub category in the main menu of the second shop, but i can't see the in Advanced parameters > Multistore.

Why there aren't the category of the second shop in Advanced parameters > Multistore? How can i fix it?