Wordpress - WP upgrade can't create directory even though perms are 777
You need to run the chown command on whole wp-content directory:
chown www-data:www-data /path/to/wp-content/ -R
Cannot creating directories even through a 777 CHMOD imply that your FTP local users does basicaly not have the permission to write files on your machine, to fix that try to edit your vsftpd.conf file and check that write_enable is equal to YES
Edit vsftp.conf file
sudo vim /etc/vsftpd.conf
then uncomment the existing line (or set it's value to YES)
write_enable=YES
The fix turned out to be to change vsftp
's permissions in the vsftp
config file.