SharePoint 2019 - Could not load file 'Microsoft.Office.Excel.WebUI.Internal, Version=16.0.0.0

[Piscus]

It seems that SharePoint 2019 (at least on version 16.0.10342.12113) is missing the Microsoft.Office.Excel.WebUI.Internal.dll  I am not sure if this was just done on purpose or just a miss from Microsoft.

Missing that dll caused Excel Web Online not to render in PerformancePoint (yes, I know. PerformancePoint.... Sigh)

Error Message:

Sorry, something went wrong
Could not load file or assembly 'Microsoft.Office.Excel.WebUI.Internal, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c' or one of its dependencies. The system cannot find the file specified.

Fix:

I grabbed the dll from C:\Windows\Microsoft.NET\assembly\GAC_MSIL\Microsoft.Office.Excel.WebUI.Internal\v4.0_16.0.0.0__71e9bce111e9429c on the SharePoint 2016 Server and copied to SharePoint 2019.

I also modified the webconfig file with the following entries:

< dependentAssembly>   
 < assemblyIdentity name="Microsoft.Office.Excel.WebUI.Internal" publicKeyToken="71e9bce111e9429c" />   
 < !-- Assembly versions can be redirected in application, publisher policy, or machine configuration files. -->   
 < bindingRedirect oldVersion="15.0.0.0" newVersion="16.0.0.0"/>   
 < /dependentAssembly>  
 
 <SafeControl Assembly="Microsoft.Office.Excel.WebUI.Internal, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" Namespace="Microsoft.Office.Excel.WebUI.Internal" TypeName="*" />
 <SafeControl Assembly="Microsoft.Office.Excel.WebUI.Internal, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" Namespace="Microsoft.Office.Excel.WebUI.Internal" TypeName="*" />
 <SafeControl Assembly="Microsoft.Office.Excel.WebUI.Internal, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" Namespace="Microsoft.Office.Excel.WebUI.Internal" TypeName="*" />
 <SafeControl Assembly="Microsoft.Office.Excel.WebUI.Internal, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" Namespace="Microsoft.Office.Excel.WebUI.Internal" TypeName="*" />

Just posting here in case might help someone else.  Not sure what happened but it seems Microsoft missed that dll. 

[#2]

@Piscus  i have added the DLL and edited web.config file. still i am getting the same error even after doing IISRESET and server reboot. Please assist.