Can anyone please tell me how to fix the error message showing while I am completing the Build a Simple Flow task. After adding contact1.firstName and contact1.lastName on the properties pane and on clicking done, the error message shows up.

Hello Pablo

I am working on completing the "Build a simple Flow" task. I am still working on the first stage of building the simple flow and encountering the problem posted. I have checked everything and I still can't find where the error is coming from and I really cannot move forward without rectifying this error. Please I really need help with this.

Kind regards

Caroline