When attempting to view a folder for a record in Salesforce, the error "you do not have sufficient privileges to access this page".
Cause
This error presents itself for all users when Apex controller access has not been granted by the Salesforce admin.
Resolution
In order to clear this error, the Salesforce admin will need to grant Apex controller access to users in Salesforce. The Salesforce article below assists with this process:
platform_swarm_kb