In activity stream, you might encounter a message such as:
Phrases 1dbb1f96d2b25755ec8ce882766596c150efecc7 and aaa97c82019600566b80fe5645341518337208ae in Czech cannot be exported correctly - malformed XML. Skipping.
This means that the translation cannot be exported into XML because the translator probably didn't insert tags correctly, didn't close them etc.
Please verify these translations and try again.