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Assume that you have Microsoft SQL Server Analysis Services (SSAS) installed on Microsoft SQL Server 2016 and SQL Server 2017. When you use Data Analysis Expressions (DAX) measures in Power BI table visualizations, you may receive the following error message:

An unexpected error occurred (file FileName\FilePath, line LineNumber, function 'FunctionName<class ClassName>::ExecSpool')

This issue may occur in measures in the following scenarios:

  • Reference another measure in a VAR assignment.

  • The main measure is used in a Table visualization.

  • The same measure works fine in a Card visualization on the same page.

  • The same measure works fine in DAX Studio.


This fix is included in the following updates for SQL Server:

          Cumulative Update 8 for SQL Server 2017

Cumulative Update 1 for SQL Server 2016 Service Pack 2

Cumulative Update 9 for SQL Server 2016 Service Pack 1

About SQL Server builds

Each new build for SQL Server 2016 contains all the hotfixes and security fixes that were in the previous build. We recommend that you install the latest build for SQL Server:

Latest cumulative update for SQL Server 2017

latest build for SQL Server 2016


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


Learn about the terminology Microsoft uses to describe software updates.

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