I went to go run a manual sync of the User Profile Service in SharePoint, and was unable to get to the Service Application.  After reviewing the ULS logs, I found this error:

The Execute method of job definition Microsoft.Office.Server.UserProfiles.UserProfileImportJob (ID 4bac9cbc-1a7a-40bd-9372-fc3c309077ff) threw an exception. More information is included below.

UserProfileConfigManager.StartSynchronizationForOneManagementAgent: Unexpected exception: System.ServiceModel.EndpointNotFoundException: Could not connect to http://<server:port>/ResourceManagementService/MEX. TCP error code 10061: No connection could be made because the target machine actively refused it IP address:port. ---> System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it IP address:port.

Luckily this error has an easy fix.  This error occurred because one of the two ForeFront Identity Manager services that the User Profile Service depends on wasn’t started.  Go into Services.msc and check to ensure both services are started:


You should be able to start the service without an issue and this should allow you to connect to the User Profile Service again. 

I will give a strong word of caution here though.  The User Profile Service can be touchy and when functioning properly, the services does not stop for no reason.  I would be sure to keep a close eye on it and if it happens more than once or twice, I would investigate further to ensure you have configured the UPS properly with all service accounts having the proper permissions.  You can read more about the requirements at the following resources:

I would strongly encourage all to apply the latest cumulative update possible (though SP1 is releasing soon) as they have many updates and fixes for the User Profile Service.