Symptoms
Assume that you have SQL Server Analysis Services (SSAS) installed on Microsoft SQL Server. When you run a Multidimensional Expressions (MDX) query that was generated by Microsoft Excel, and an uninitialized variable is accessed, you receive the following error message:
Executing the query ...
Internal error: An unexpected exception occurred.
Resolution
This problem is fixed in the following updates for SQL Server:
Cumulative Update 11 for SQL Server 2017
Cumulative Update 3 for SQL Server 2016 Service Pack 2
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.
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 Microsoft uses to describe software updates.