Error in Calculate Client Security Hash

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Hi ,
In Calculate Client Security Hash in level 3- Advanced Training While run the File it is showing Runtime execution error in System1_NavigateTo_Workitem, Can any one Explain me why it is getting error.
Thank you.

@harishraj

When we are trying to assign Null value then will get this error. Could you please run the process in Debug mode and check it once.

Delete that invoked workflow, try again to invoke the same workflow where necessary and pass the necessary arguments…
Before invoking keep it in System1 Folder…

Ya i have tried it in Debug mode after opening the URL it is directly killing process and its showing nothing in debug @lakshman

Hi , you might have missed mapping an argument to another argument in invoke workflow file
Pls check that area

Or

Argument is not carrying any value which you might be using inside invoked workflow

Whether you tried this???..

yes @Manish540 error is solved.
Thank you