Here is a real scenario from one of the blog readers:
When I log into SharePoint as system account, I can rate documents. When I log on using another account, who is a member of contribute group, when I try to rate document, sharepoint keeps prompting for user credentials, do you know why this happens?
This mainly depends on how the SharePoint 2010 setup was donw in a first place as well as how User Profile was set up. First thing to check is User Profile Service application:
1. Navigate to your Central Admin : http://[central admin URL]/_admin/ServiceApplications.aspx
2. Select your User Profile Service Application and click Properties:
3. Take a note of your Application Pool account for your SharePoint web service system :
4. It’s also best to run your : Profile Database, Synch Database, and Social Tagging DB under Windows Auth.
5. Now go back to the window from Step #2 and click Permissions.
6. Here, specify the account (from Step #4) and any other optional accounts that have access to invoke User Profile service application. Typically, you would add the service accounts of web applications connecting to this service application to the list below. So if you have mysites that has arating service enabled – make sure it’s here as well.
That’s it – click ok. I also would recycle IIS and WSS Time Service and see if the problem got solved.
