SharePoint Error: Access Denied. You do not have permission to perform this action or access this resource

 This error can occur at many places e.g. creating a workflow, accessing list items or user permissions using CSOM, or simply trying to navigate to the settings page. Its meaning is pretty straight forward. In dev server setup it can be resolved by providing full control permissions to the dev users.

• Go to Central Administration
• Go to Application Management
• Go to Manage Web Application
• Select the web application we’re talking about
• Click User Policy
• Add Users
• Click Next
• Fill in domain\superuser
• Select Full Control
• Click OK

For staging and production environments though, we should be careful to assing only the required permissions.

Reference: http://www.sharepointchick.com/archive/2010/10/06/resolving-the-super-user-account-utilized-by-the-cache-is.aspx