I displayed my outline.
I chose File/Export/Outliner Contents as CSV
I chose "C:\temp\outline.csv as the filename.
I chose OK.
There was no outline.csv file in the c:\temp folder.
After a bit of investigating, I found the following file in the Scrivener backup folder:
“c temp outline csv.csv”
I’ve now figured out how you intended it to work, but a Windows user has a certain expectation about how “Save As” and “Export” work, and because this works differently, others will be confused as I was.
Consider making it easy on yourself and the users by having it just use a normal Save As dialog.