How can I resolve the error "Could not load file or assembly 'Microsoft.DataWarehouse.AS'" in SSIS?
I was able to defeat the error by uninstalling these two extensions for Visual Studio:


Microsoft Reporting Services Projects
Microsoft Analysis Services Projects


Then I reinstalled the latest SSDT for VS 2017. 

On installation, I chose all 3 options (Analysis Services, Integration Services, Reporting Services). Although I would bet the only requirement to solve the problem would be AS as the original error referenced AS specifically.