Secure Topics for Salesforce Sites and Portals (Critical Update)
Where: This change applies to Salesforce Sites in Salesforce Classic in Enterprise, Performance, Unlimited, and Developer editions. This change also applies to Portals created before Summer ’13 in Salesforce Classic in Professional, Enterprise, Performance, Unlimited, and Developer editions. This change doesn’t apply to communities and portals created after Summer ’13.
When: This critical update is enforced on August 26, 2018.
How: After activation if you want guest and authenticated external users in Salesforce Sites and Portals to have access to topics, enter Chatter in the Quick Find box in Setup. Select Chatter Settings, and in the Topics section select Allow topics in Salesforce Sites and Portals.