I am trying to create labels using Word for Mac 2011 using the Mail Merge Manager. When I get to the step where you choose a data source, the system will not open the Excel for Mac document where my addresses are. I first get a Convert File box and am asked to choose which type of Excel spreadsheet I am using and then I get a warning message when I tell it to go ahead and convert. Then it says "There was an error opening the file." My husband is experiencing the exact same thing on his Mac using an entirely different Excel doc. Help! I'm pretty sure this worked for me at Christmas time, which makes it even weirder.