Passing Datatable using Launch Interactive workflow

LaunchWorkflowInteractive creates a separate robot process (same as InvokeWorkflowFile with Isolated = true). Whenever you’re passing things across process boundaries, they’re fully serialized and deserialized on the other side.
Since, as far as I know, Json serialization is used for that (specifically Newtonsoft’s implementation), there are some caveats with passing complex types (assuming they’re serializable at all).
For dt specific stuff you can check in this thread:

That’s correct. Only actual values are serialized and DT schema is inferred on deserialization based on first row values (or in other words - whatever you have in first row will dictate what Type that Column will have after deserialization). If you pass an empty DT, there’s no data to create columns from.

Just to repeat - from my knowledge this is not a UiPath specific error, it’s from Newtonsoft.Json.