Someone shared and protected a workbook that I created. I went to
Tools>Sharing and unshared the workbook. Now when I try to make changes and
save them I get an error that says "You must first unprotect the document".
When I try to do this, however, the unprotect option on the Tools>Protection
menu is not available.

I have noticed that it says [Group] in the title bar. How do i turn that
option off?