How to Troubleshoot Broken Workflow

Permanently deleted user

1. August 2017 00:35

I'm having trouble with a workflow I'm building in Essentials 4.7 and no matter how I simplify it to find the problem, it remains broken. The error reads Unhandled exception: 'Value cannot be null. Parameter name: input' in activity '1.1: Text Search'. Text Search is the name my outermost Sequence activity and nothing anywhere has a parameter named input.

 

At it's simplest, when the workflow is working, I have a very vanilla Input form (1 group, 1 textbox, no buttons, an output argument variable, and no RuntimeModifications) followed by an alert that displays the value I entered.

 

The next desired step is a series of nested ifs to decide what to do with the input string. It was working great in the simulator until it started getting the above message after I entered the last few nested levels in one push. I don't know what caused that message and there seems to be nothing I can do to find it or fix it.

 

I made a copy of the workflow and started deleting things. At last, I deleted all of the if activities, leaving only the input form. Even this cannot be run in the simulator; it raises this same error.

 

What does this mean and what can I do about it?

 

Thanks,

 

Martha

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  Permanently deleted user

  1. August 2017 15:37

  Hi Martha,

   

  It sounds like what you have is a variable that you are expecting to be defined, but is not.  Hence the "Value cannot be null" part of the message. 

   

  These can be tricky, the way that I find works best for troubleshooting these, is to do the following:

   

  1) In the workflow designer, search for activity 1.1

   

  2) Look at the variables that you are using

   

  3) Just before the activity, put an alert box, and use the variables as the body of the text box

   

  4) Run the workflow

   

  If you get any empty alert boxes, look at the variable that you are using in them, then backtrack through your workflow to figure out where they are supposed to be defined.  From there, you can start to figure out why the variable is blank.  

   

  If all else fails, please open a support case, as we are happy to assist you with this directly :)

   

  I hope this helps!

   

  Danny

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  Permanently deleted user

  2. August 2017 20:35

  Thank you, Danny,

   

  I'll give the alert box a go. I'd love not to have to build this entire thing again.

   

  Martha

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  Permanently deleted user

  2. August 2017 21:21

  I am back in business, Danny, thank you, though I never got to the alert box. Item 1.1 is the DisplayForm to get the runtime input. It needs no input other than what is typed in. The output string variable was declared, but didn't have a default value or a 'new' expression. Just setting that to "" seems to have cured what ails me. Lesson learned.

   

  Thanks,

   

  Martha

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  Permanently deleted user

  2. August 2017 21:35

  That's great Martha, thanks for updating your post with your solution!  

   

  Cheers,

   

  Danny

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