Microsoft has warned that starting December 11, 2009, customers using Office 2003 will not be able to open Office 2003 documents protected with the Rights Management Service (RMS) or save Office 2003 documents protected with RMS, Cnet has reported. "We are working to resolve this issue as quickly as possible and we will provide customers a solution as soon as we can. Any new updates and we will post the information here," the company said its Office Sustained Engineering blog.