The way to get your Screenwriter 4 file (or any file written in another program) is to save as or export your original file as a text-only file, then open the text file in Final Draft and let Final Draft reformat the text as a script.
Keep in mind that we don't support other programs, but this is how most users are able to convert their Screenwriter 4 files. If you have difficulty with this procedure you should contact their technical support for help on exporting.
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