Symptoms
Assume that you use Microsoft SQL Server 2014 Analysis Services (SSAS 2014) in Tabular mode. When you execute a query that uses a Distinct Count calculation, values may be missing from the query result.
Resolution
This issue is fixed in the following cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.