Error while passing datatable using invoke workflow


Hi i am trying to pass datatable as an argument with invoke workflow i am getting error “object reference not set to an instance of an object”, I have just edited the example of Argument given in uipath website i am attaching my workflow below please do let me know what i am doing wrong.

Argument1.xaml (7.2 KB)
Argument2.xaml (5.6 KB)


Hi @Nara,

You cannot convert datatable.tostring (In your case it is Extractdtfinal.tostring) instead try for each rowe activity to output values in datatable. refer -

Vikas Reddy


@vikas_reddy_Vicky thanx for the info got it i have just corrected my error it was because of some other reason.
Your point is also correct on datatable .Tostring noted that.

I had initialised Extractdt in variable part also and argument part also in argument1 workflow after removing Extractdt from variable part the error was gone and also i added one more step write CSV to check whether i am getting data from the datatable or not.
attaching the workflow below.
Thank you
Argument2.xaml (6.5 KB)
Argument1.xaml (7.4 KB)



Vikas Reddy