Hello all. I'm encountering a problem with my Word 2013, and cannot figure out how to fix it.

I was working with several documents that were password-restricted from editing. After doing so, I opened several other documents that previously had absolutely no restrictions on them. After making changes, I saved these documents into various locations.

Now, when I open any one of this second set of documents, I am unable to make changes! However, when I enter the password that restricted all of the first set of documents, I am able to edit this latter set. At no time during any Save process have I been prompted to enter any kind of password; instead, the system seems to be merely assigning one to me!

Two additional points of info: a) I can save a document without the password, and it appears fine until I close the document. When I reopen it, the password is magically inserted. b) when I go into Info > Protect Document > Encrypt With Password, the entry is blank, yet there is a password that is restricting my ability to edit the document! Thankfully I know it, but still . . . .

What have I done, and how can I get these passwords removed from documents I don't want to protect?!? Many thanks for your expertise and guidance.