Error in a field I dont recognize

Error in a field I dont recognize

Hello,


When I try and test my very simple flow I keep encountering more and more problems.
after solving a few, my recent one is that when I try and check the "output" section in my flow, it says "Invalid input for field1. The expected input type is date."

I dont have a field called "field1" and I have no idea where to start looking for a solution.. 

I have attached a printscreen for reference.

Thanks!