Template files not writable

Hello, I’m having an issue with my template files for wiki module in EE. I want to style it differently, so I copied entire default template with FTP and created a new folder with different name and all same files inside. I made sure that folders and files have same persmissons on server as the original folder. When I log in to EE I can se the new set for template files under design, but when I try to edit them every file in the new folder shows:

“Note: This file is not writable

You will not be able to save changes to this template until it is given write permissions for this server.”

But as I already stated, all folders, subfolders and files have same permissons as the default theme that I copied them from. Meanwhile files in the original theme can be edited in EE withouth any issues.

Does anyone know what the issue might be and how to solve it??? Thanks in advance!