Follow Button Grey out, No "Post Configurations" option in Settings.

Hello, 

We're trying to set up activity feeds but seem unable to follow any type of record. When we click on the "..." "More" button there is no Star "Follow" button in the drop down list. When we select a contact in advanced find the Star "Follow" button is greyed out and if you hover over it it tells you that "This button is currently disabled". I'm set up as system admin so I don't know if it's a permissions problem?

I did find the link here https://community.dynamics.com/crm/f/117/p/201314/520467#520467 which suggests changing permission settings in the "Post Configurations" area. My problem is that I can't seem to find the "Post Configurations" area. This article https://social.microsoft.com/Forums/en-US/cd512c81-3247-471a-ac71-0f9a578809bd/how-can-i-configure-the-activity-feeds-wall-in-ms-dynamics-crm-2013?forum=crmdevelopment says that it is directly within "Settings" but I don't see it as an option when I select "Settings". When I open the "Customize the System" window, I don't see "Post Configurations" listed under any component. 

We are in CRM dynamics online but we're being hosted in a Citrix cloud environment (rather than Microsoft cloud) so our system hasn't updated automatically and is stuck in 2013. 

Thanks in advance for any help. 

Kate