I'm having the same problem when saving a particular document - this was started from scratch using the final release version of Publisher, i.e. not the Beta.
Crashes every time attempting to save or save-as.
What I'm attempting to do is adjust a pinned item (floating image box), and also use the decoration panel so set a horizontal rule before paragraphs.
I've attached the crash log if it is of any help!
I can start a new document from scratch, put something in it, and successfully save it, so the problem seems to be in the one mentioned above.
Phil in Welland crash log.pdf