Selecting Data from a DT where datas don't exist in another DT


I’m basically trying to filter one DataTable(DT1), where the data from another Datatable(DT2) should not be included. I tried Filter Data Table activity but it doesn’t seem to be working.
I’ve also tried with this link:

DT1.AsEnumerable().Where(function(row) Not DT2.AsEnumerable().Select(function(r) r.Field(Of string)(“COLUMN4”)).Any(function(x) x = row.Field(Of string)(“COLUMN4”))).CopyToDataTable()

But I’m getting the error “specified cast is not valid”.
The data columns I’m comparing is Int32 (DT1) and String (DT2)

If anyone could help me on this I would really appreciate.

can you explain the scenario with example