The title of the post is a bit of a misnomer because the SUMIF function in Excel does not allow you to have more than condition. Excel 2007 introduced the SUMIFS function which allowed for multiple conditions. However, if you are using any version prior to Excel 2007 or if the persons who will be using your Excel workbook will be using a version prior to Excel 2007, then the SUMIF function will throw up an error.
It had to be coming. As part of its monthly patches release, Microsoft will be releasing eight security bulletins with patches for a several Windows and Office vulnerabilities. These include the patches for Microsoft Word which had remained unpatched last month.