Occasionally when working in the MultiTrans XLIFF Editor, your file can become corrupt and you can no longer open it. In these cases, you can always open a support case via https://gateway.sdl.com and we will attempt to repair the file.
If however you would like to attempt to fix the file yourself, or you'd simply like to learn more about the underlying structure of the XLIFF file, then see the PDF document below which explain this in some detail. This document assumes basic knowledge of XML.
Also download the MultiTrans XLIFF schema file contained in this ZIP folder. Instructions on how to use this to validate the XLIFF file are contained in the PDF above.