I tried this:
cd /opt/lampp/htdocs/
sudo usermod -a -G daemon john
sudo find . -exec chown john:daemon {} +
sudo find . -type f -exec chmod 664 {} +
sudo find . -type d -exec chmod 775 {} +cd <-problem child
It goes fine until the last command which gives me "find: missing argument to `-exec'"
So Wordpress cannot add or delete plugins etc... thoughts?
find ... -exec ... +and there are more characters after+then you get the error you describe.