Assume that you use Microsoft SQL Server 2017 Analysis Services (SSAS), when you execute some specified queries, it will take much longer time than SSAS 2014.
This fix is included in the following update for SQL Server:
Cumulative Update 8 for SQL Server 2017
About SQL Server builds
Each new build for SQL Server contains all the hotfixes and security fixes that were in the previous build. We recommend that you install the latest build for your version of SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the standard terminology Microsoft uses to describe software updates.