User Input task error Unable to create one or more variables, variable name already in use

Question

I have a User Input Task in a process model and I am getting this error message when I set the interface for the node. I can't find where this variable is in use. 
 
 I do have a process variable for spkrEventDocuments and I set it to the process variable in the Data Inputs for the User Input Task 
 
 There are no Outputs defined.

Mathieu Drouin · Answer

I believe you need to check "multiple" on that 2nd screenshot.

Chris.Gillespie · Answer

Thanks. I found out what the issue was on the error message. I added the variable in the Data Input tab before I reloaded the form. I deleted the variable, then reloaded the form and the variable populated correctly in the Forms Tab.