Thank you, leroydouglas
I'm still trying to figure out what is going on with this issue.
From your reply, I now gather that there is no "general" owner password for Preview--passwords are applied to individual documents.
One possible explanation for my experience is that there is some kind of default on my Preview that causes all documents to be password protected (with an unknown password) when I save or export them.
If this is the case, does anyone know how to make the default so that there is NO PASSWORD?
I looked at the Help article you suggested, but it did not explain how to PREVENT a password from being applied.
Another possible explanation for what is going on is that the PDF I am working with (which I got off the SSA.gov website) has some kind of default password function going on. I am able to open the document no problem, but every time I save or export it, there is an unknown password applied. So I can't open saved or exported versions of the doc, nor can I open the original doc anymore -- I need to download it fresh from SSA to work with it.
Does anyone have suggestions for how I can work with this PDF password free? I just want to fill out the form and save the filled-out version without a password.
Thank You