Windows Unified Login Authentication on DSM Web Console shows WAC login popup:
"X Error: Auto Login Failure - May be its not Configured Properly - User Normal Login"
Client Automation - r14.x versions
Missing permission for the IIS Application Pool Identity DefaultAppPoll.
In Computer Management > Services and Applications > Internet Information Services (IIS) Manager,
expand the Server under Connections:
Right-click on the DSM_WebService, then Edit Permissions:
Select the Security tab in bin Properties, then Edit:
Click on Add:
Add the user DefaultAppPool (Hostname\DefaultAppPool) and click Ok:
Give the Full Control and click Ok and Apply:
Enter on site DSM_WebService:
Click on Providers and verify the order:
Click on Advanced Settings and check the selections:
caf stop tomcat
iisrestart
caf start tomcat
See ref. link: