sfst - 2017-06-27

Can you please specify the format of the file you opened? (Is it .mpp?)

Is it possible to upload the file?

Can you please try the Save as?

Please pay close attention what is in "Files of type:", when I had "All Files" it saved an XML file with the .POD extension, which needed renaming, otherwise it could not be opened again.
(As Windows by default hides the known file extensions this can be a difficult task on some computers.)