Object reference is not set to an instance of an object in invoke workflow

I am getting the following error as in the snap please do needful to resolve it.

@ushu
@nikhil.girish
@Nithinkrishna
@ppr

@HeartCatcher This might be because the variable or argument has no value. Please run the process in debug mode and see exactly where it is coming

Hi @HeartCatcher

the argument has no value that might be the reason kindly recheck and debug step by step

Hi @HeartCatcher

Check the Invoke Login Work flow Arguments, debug and do a step into for each Activity and check the Values.

Thanks

get trained with the resources from here as debugging is an essential action we do in such sceanrio