Delete Cache Problem Related to Permission
You can delete the cache both automatically, manually.
If you have a permission problem with /wp-content/cache/ folder, you get the warning above.
Solution
1. Set the permissions of the following folders as below
/wp-content/cache 755
/wp-content/cache/all 755
/wp-content/cache/wpfc-minified 755
/wp-content/cache/wpfc-mobile-cache 755
2. Set the owner of the following folders as below
If you are still getting the permission warning although you have changed the permissions as above, you have a problem with the owner of the folders. As you see on the image below, the owner of the /all/ is different from others.
You need to set the owner of the folder with your username via terminal as below if you have dedicated server or VPS.
sudo chown -R USERNAME:USERNAME /YOUR_WORDPRESS_INSTALLED_PATH/
Note: If you have a hosting package, you cannot set the owner. In this case, you need to contact to your hosting provider.
