Solved by siteground support
They told me:”The memcached process was not properly started on the server so I had to contact our system administrators who have found the cause of this and started it. The issue should not reoccur.”
Hello Ivan
I have exactly the same problem of vsimons: even tough activated from cpanel, Memcached remains grayed. I have the latest version of wordpress
the domain is http://www.leftygardens.com
Do I have to open a ticket? Where?
Thank you for your time
C
