Problem: End-user wants to copy-paste a bunch of rows from Excel to SharePoint using Datasheet view. Datasheet view doesn’t allow users to paste the data for Person or Group type column! It gives the error message:
The Text entered for the “Person or Group column” isn’t an item from the list. Select an item from the list, or enter text that matches one of the
This is by design! SharePoint 2010 datasheet view uses Microsoft access run time engine, which doesn’t have an interface to connect and resolve user names from the active directory (or any other authentication provider). So, it fetches user names from the User information list of the SharePoint site collection. That being said: If you enter a new user who is not there in UIL, the datasheet view can’t resolve it!
To fix this problem, before copy-pasting to datasheet view, we should have them all in the user information list! So, add all users from the people picker column values to the SharePoint site (E.g., you can add them to any group like site visitors) that will add users to UIL automatically!