Scientific Word/Workplace ⇒ Filter not valid error

[palaremzi]

I've created the attached file using SWP but now when I try to open it gives me this message: "The file is not valid for the selected filter". I've tried to open it with LyX and WinEdt but no luck!

The file is part of my lecture notes and took me quite a while to prepare, I don't want to rewrite the whole thing.

Any suggestions welcome! In case you want to try opening the file I am attaching it. I would be most grateful if you could open it and pm me the file.

Thanks