This issue actually caused by different users who wants to write/read
file but denied cause different ownership. maybe you as 'root' installed laravel before then you login into your site as 'laravel' user where 'laravel' the default ownership, so this is the actually real issue here. So when user 'laravel' want to read/write all file in disk as default, to be denied, cause that file has ownership by 'root'.
To solving this problem you can follow like this:
sudo chown -hR your-user-name /root /nameforlder
or in my case
sudo chown -hR igmcoid /root /sublaravel
Footnote:
root
as name first ownership who installed beforeyour-user-name
as the default ownership who actually write/read in site.namefolder
as name folder that want you change the ownership.