First the nitty gritty - I am running the latest release of Finale - 18.104.22.168 on Windows 10, which should also be fairly current, as it auto updates.
I have had this happen to me twice...... I am editing and adding to a work that I have created in this release (I am a newbie to Finale, after using another product for several years. I have never had a prior release of Finale installed.) All seems to be normal - I am moving forward, with the work, encountering no difficulties that I am aware of. Then I go to save the document, which has been previously saved, closed, and reopened several times. The save fails, with a message that states that a file is missing - from the name I would say it is a temp file used in the editing process. Sorry, I don't have the exact message. It gets worse, though - there is an open save dialog box now on the screen, open to the directory that I am working from. There is nothing in the directory - the one file that I opened to start the editing is also gone.
I am able to do a select all, open a new document, and then save into the new document, so I haven't lost all of my work, but my blood pressure and heart rate were certainly elevated.
The document in question in not what I would consider large - approximately 230K; it contains about 15 instruments, and is currently 96 measures in length.
One thing I have noticed is that Windows 10 is in a "reboot required state" this time; not sure about the first occurance, as that was about a week ago. Is this a bug with Finale, Windows, or something else?
Thanks for your assistance.
PS - this does not occur at a predictable place that I am aware of, and certainly not every time I work on the composition. I would have trouble trying to recreate the problem, but it has happened twice.