for LINQ we dont have to add additional packages
we would recommend to add AsEnumerable to dt → dt.AsEnumerable
maybe you can share with us some sample data
also have a look here:
[FirstAid] Handling of The source contains no DataRows exception - News / Tutorials - UiPath Community Forum
[HowTo] LINQ (VB.Net) Learning Catalogue - Help / Something Else - UiPath Community Forum