SSAS:Dynamic security is not working unexpectedly -

the problem when inserted new users user table .dynamic security based on dimuser , well-known mdx scripts on state attribute

nonempty( [state].[state].members, (strtomember([users].[username].&[+username()+]),[meaures].[userstatecount])) 

this used 9 months , worked fine . 2 week security has weird behavior , show empty report users , reports .visual studio 2015 , sql 2016 .

a screenshot error or error description lot, consider this, in domains, analysis services may perceive user name expected domain\username or localcomputer\username, in cases may return upn formatting of user's name such username@domain.com . therefore may need accommodate upn possibility if write mdx code relies upon username() mdx function.

another consideration, verify system administrator don't migrate on ad or on cloud services.

hope helps!