Hello SharePointers,

When you are trying to create a document set using Powershell in SharePoint online environment, if you miss to load the  the document set library/dlls , You will get this message “unable to find type [Microsoft.SharePoint.Client.DocumentSet.DocumentSet- SharePoint online Powershell”.

Here is the instance below. Please ensure that all the below dlls are loaded in your script .

# Paths to SDK. Please verify location on your computer.
Add-Type -Path “c:\Program Files\Common Files\microsoft shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll”
Add-Type -Path “c:\Program Files\Common Files\microsoft shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll”
Add-Type -Path “c:\Program Files\Common Files\microsoft shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.DocumentManagement.dll”

Happy SharePointing Folks 🙂