This is a strange one. Jane gets an email with a Word document attached. She gets "Word experienced an error trying to open the file" and suggests that it's permissions, hard drive space, or corrupted. Jane saves the attachment to her hard drive and gets the same error message when she tries to open it.

Jane forwards the email to Bob. Bob can open the attachment normally. Bob forwards Jane's email back to her and Jane can open the attachment normally.

My first thought is to re-install Office on Jane's computer, but I'd like to know if there is a different option.