sql-server - services - sql server windows authentication not working

Analysis Services Only Windows Authentication (3)

Actually needing "Active Directory" isn't really true.

You can trick OS's by logging into your PC in any domain with the same User and Password as the account on the other server that's running SSAS. I do it all the time. By default you'll get access if the domains are different but the user/pass is exact.

Is it true that Analysis Services ONLY supports windows authentication?

Yes, it does. Quote from MSDN

"SQL Server Analysis Services supports only Windows Authentication"

You'll need active directory, Refer to the following kb on how to set it up http://support.microsoft.com/kb/917409