Sorry for late reply, we’ve just finish Summer Holiday

With your case please try set permission for that file to 777 or 644. You need set permission via SSH or Cpanel tool of your hosting. If your issue still not solve please give me account to access cpanel of your hosting

P/S: You can also try instal our theme on your local to check this issue, because on your local you dont need set permission for file, folder.
And dont forget Set as private reply if you want to protect your info