Cause: The document was originally created in an earlier version of Word.
Solution: Save the document in the .docx file format.
Important: The following procedure changes the file format of the document. If you plan to share the document with people who use an earlier version of Word, you might want to work in compatibility mode and leave the document in its current file format. This is because other people may be unable to edit parts of a document that you create by using new or improved features in Word 2011.
On the File menu, click Save As.
On the Format pop-up menu, click Word Document (.docx).
Make sure that the Maintain compatibility with Word 98-2004 check box is clear, and then click Save.
Note: When you open a document that contains pictures and was created in an earlier version of Word, the available options for formatting the pictures are limited. When you save the document in the latest format, the pictures are updated and all formatting options become available.