Can't Edit Microsoft Word Document Mac
Describes an issue that occurs when you double-click or drag a file from an earlier version of Word for Mac onto a Word 2008 for Mac program icon. In this scenario, the file doesn't open. When you open a protected document, Microsoft Word 2010 restricts what you can change based on whether the document owner granted you permission to make changes to a specific part of the document. The Restrict Formatting and Editing task pane displays buttons for moving to the regions of the document that you have permission to change.