What could be causing this unexpected error that is shutting down my workflow on a SharePoint list?
Error (from ULS log):
> System.ArgumentNullException: Value cannot be null. Parameter name:
I have an InfoPath form on a SharePoint list and after hitting submit, I get "The form has been closed" message. The form shuts down as soon as I submit it even though the data is written to the list and the InfoPath rules on the submit button are executed successfully. I know this because I have rules that set a field's value on submit based on what was entered into the form and that value is being written to the field in my list.
I think the problem is in the workflow (rather than the form) because the workflow history shows that "an error occurred" and the first step of the workflow (to send a notification email) does not occur now (it was working before). This workflow WAS working but seemed to stop out of the blue. I can't figure out what field in my form is returning a null for "user".
The only thing I did that precipitated the problem was that in trying to troubleshoot a different problem, I decided to create a field in the list ("role") to do a lookup for user roles (manager, depthead, etc). I then decided to delete that field and sharepoint complained with an error saying that the field "role" had been deleted and it would no longer pull up the form at all. So I just deleted the form and list webparts and re-added them to my SP page and my form came back. But then this problem began.
If anyone knows what could cause this error and how to fix it, i would be grateful! I've been troubleshooting this for several days now.