Critical Updates

This release includes updates that improve the performance, logic, and usability of Salesforce but might affect your existing customizations.

To ensure a smooth transition, each critical update has an opt-in period, which ends on the auto-activation date that’s displayed on the Critical Updates page in Setup. During this period, you can manually activate and deactivate the update as often as you need to evaluate the impact on your organization and modify affected customizations. After the opt-in period has passed, the update is automatically activated. For more details, see Critical Updates.

Serve Static Resources from the Visualforce Domain” Critical Update Postponed
In Summer ’15, we changed the domain from which static resources are served. This change was released as a critical update named “Serve Static Resources from the Visualforce Domain” and was scheduled for auto-activation in Spring ’16. The auto-activation date has been postponed until Summer ’16.
PageReference getContent() and getContentAsPDF() Methods Behave as Callouts” Critical Update Postponed
In Summer ’15, we changed the behavior of the getContent() and getContentAsPDF() methods of the PageReference object. This change was released as a critical update named “PageReference getContent() and getContentAsPDF() Methods Behave as Callouts” and was scheduled for auto-activation in Spring ’16. The auto-activation date has been postponed until Summer ’16.
Encryption Key Management Permission Removed From Admin Profile
Admins must now actively assign the ability to perform key management roles. The "Manage Encryption Keys" permission will be revoked for the standard admin profile when you activate this Critical Update.

Custom profiles that include the Manage Encryption Keys permission are not affected. Any user who has the permission via a custom profile or permission set will still have the permission.