I can't open my client's idml/xliff files (extracted from InDesign

Hi, my client has Studio 2014 SP2. I have Studio 2014 SP2... but I can't open his idml/xliff files (extracted from InDesign), and he claims that he can. I get 2 errors. "Data at the root level is invalid", and "file created by an unsupported version of Adobe InDesign"