Cannot login to SSAS 2008 from SSMS?

Issue: 
When I tried to connect to a named instance of SQL Server 2008 Analysis Services (SSAS) by using SQL Server Management Studio, I received the following error message intermittently:

The 'InstanceName' instance was not found on the 'ServerName' server. (Microsoft.AnalysisServices.AdomdClient)

Solution:
 When I checked my services all the services was up & running, even I had restarted my SSAS services, but it didn't help me. but the issue was resolved after restart the SQL Server Browser service. 

If you aware, how to to restart any windows services that related SQL server then Ignore the steps below:

Steps to Restart "SQL Server Browser" service:
1.On the Start menu, right-click My Computer, and then click Manage.
2.In Computer Management, expand Services and Applications, and then click Services.
3.In the list of services, double-click SQL Server Browser.
4.In the SQL Server Browser Properties window, click Start or Stop.
5.When the service starts or stops, click OK.

After restarting the "SQL Server Browser" service, I tried to connect SSAS via SSMS, it works. Hope it may help you.