I couldn't figure out where you were getting the Button | function = "save" condition. Though I did create a similar test using your suggested actions. I don't care so much about loading right now cause I can't write. Is there a disadvantage to spelling out the entire path I want the file to go instead of using AppFolder? Remember I'm just trying to get the program to write a file. Which isn't happening no matter what I do.
So I created the simplest of programs. All it has is a button and a text box. Click the button and it prints the appfolder location to the text box.
In Preview mode: nothing shows up
In Exported mode: nothing shows up
In Exported and Uploaded to Web mode: nothing shows up