Yes in order to Import the Homepage widgets using the Widget Importer you have to upload a .wie file. I created a .wie file here if you haven’t seen it already – https://appfinite.com/theme-setup/vintage-theme-setup/ Here’s the direct link – https://appfinite.com/theme-setup/vintage-theme-setup/#ihp
Is this what you’re trying to do and it’s still not working? If so, can you double check the file you’re uploading and make sure it has the .wie extension? I’ve seen a couple people mention that their Computer/Operating System converts the .wie file into a .txt file (when it shouldn’t) which means the file won’t upload to the importer. If that’s not it and it’s still not working, then I can upload it for you if you want. All I would need is a Temporary login and I can have it uploaded in 2 seconds…..Just let me know
Also, take a look at my Reply/Comment from your other post a couple months ago. I explain the differences between what the default WordPress XML files can upload VS the Widget (.wie) files can.