Getting this recurring error for no apparent reason.
I have a desktop flow that pulls data from an excel sheet and parses in a certain way, then stores the data as a datatable in an output variable. (It's just a normal datatable with column headers:)

The flow works 100% fine, except it consistently fails on the last action, regardless of what that action is, with the following error:
System.NotImplementedException: The method or operation is not implemented.
at Microsoft.Flow.RPA.Desktop.Robin.Engine.Types.TypeAdapters.TypeAdapter`1.ToSerializedValue()
at Microsoft.Flow.RPA.Desktop.Robin.Engine.Types.TypeAdapters.DataTableAdapter.ToSerializedValue()
at Microsoft.Flow.RPA.Desktop.Robin.Engine.Execution.Runner.TrySetFlowsOutputArguments(ICollection`1 outputVariables)

I know it isn't actually the final action causing the error, as wrapping the final action in an "On block error" doesn't cause any change.
I suspect it's an issue with using a datatable as an output variable, maybe the column headers are causing an issue.
I also can't run the flow from any other flows with the "Run desktop flow" action, it produces the same error:
System.NotImplementedException: The method or operation is not implemented.
at Microsoft.Flow.RPA.Desktop.Robin.Engine.Types.TypeAdapters.TypeAdapter`1.ToSerializedValue()
at Microsoft.Flow.RPA.Desktop.Robin.Engine.Types.TypeAdapters.DataTableAdapter.ToSerializedValue()
at Microsoft.Flow.RPA.Desktop.Robin.Engine.Execution.Runner.TrySetFlowsOutputArguments(ICollection`1 outputVariables)
Is there a work-around for this or could there be a problem with my flow that I'm not recognising?