The export for localization feature seems to be promising especially as soon as a project becomes really big in terms of content and languages supported, but I never managet to make it work, nor in Xcode 7 not in Xcode 7.1.1.
It always failed and still fails with the same error "/usr/bin/xmllint exited with status 1" and no clue about what can be wrong.
Please advice what can be done, except for suggesting to do it through terminal, because the error message that I saw in the terminal is also not explaining anything. The interesting fact is that the file is generated, but this error makes me think the importing back will never work.
Waiting for this bug to be fixed for quite some time already....