How to fix 'Some files are not writable by WordPress' error, website cannot be changed by admin

Apart from permissions you have to change the Owner of the Files to the web server user ( most cases, especially those using apache www-data ) .

The command to do that is the below

sudo chown www-data:www-data /path/to/wordpress/ -r

the usual path of a website on a ubuntu server is /var/www/domain.com/ but of course that depends !

Wish you the best!

change all files and folders permission as follow:

enter your public_html folder and execute this two commands

find . -type d -exec chmod 0755 {} \;

find . -type f -exec chmod 0644 {} \;