Some of the reports in ConfigMgr may not work connecting to ACT.. here’s a sql fix to run on the ACT db

GRANT CONNECT to guest

GRANT SELECT ON Application_Report_Complete_vw to guest

GRANT SELECT ON Applications_vw to guest

GRANT SELECT ON Machine_Installed_App_vw to guest

GRANT SELECT ON Machines_vw to guest

GRANT SELECT ON Deployment_OS_vw to guest